Why is $ab(frac1a)b^2cb^{-3} = c$?
I'm working through some textbook exercise and am unable to solve the following exercise:
Use the basic rules of algebra to simplify the following expression:
$$abfrac{1}{a}b^2cb^{-3}$$
Within the chapter of the book in question the author has covered:
- Associative, commutative and distributive properties of an equation
- Expanding brackets
- Factoring
- Quadratic factoring
- Completing the square
The solution in the answers section is simply "$c$". The equation simplifies to $c$. I cannot for the life of me see how. The solution provided does not give the steps in between, only the final solution $c$.
How can one arrive at $c$ with all the steps in between?
algebra-precalculus
add a comment |
I'm working through some textbook exercise and am unable to solve the following exercise:
Use the basic rules of algebra to simplify the following expression:
$$abfrac{1}{a}b^2cb^{-3}$$
Within the chapter of the book in question the author has covered:
- Associative, commutative and distributive properties of an equation
- Expanding brackets
- Factoring
- Quadratic factoring
- Completing the square
The solution in the answers section is simply "$c$". The equation simplifies to $c$. I cannot for the life of me see how. The solution provided does not give the steps in between, only the final solution $c$.
How can one arrive at $c$ with all the steps in between?
algebra-precalculus
1
My +1 for good presentation of the context.
– Yves Daoust
Nov 20 '18 at 17:12
The global exponent of $a$ is $1-1$, that of $b$, $1+2-3$ and that of $c$ is $1$.
– Yves Daoust
Nov 20 '18 at 17:13
1
Here's a really helpful tutorial for MathJax formatting: math.meta.stackexchange.com/questions/5020/…. It's pretty easy to pick up!
– Robert Howard
Nov 20 '18 at 19:24
add a comment |
I'm working through some textbook exercise and am unable to solve the following exercise:
Use the basic rules of algebra to simplify the following expression:
$$abfrac{1}{a}b^2cb^{-3}$$
Within the chapter of the book in question the author has covered:
- Associative, commutative and distributive properties of an equation
- Expanding brackets
- Factoring
- Quadratic factoring
- Completing the square
The solution in the answers section is simply "$c$". The equation simplifies to $c$. I cannot for the life of me see how. The solution provided does not give the steps in between, only the final solution $c$.
How can one arrive at $c$ with all the steps in between?
algebra-precalculus
I'm working through some textbook exercise and am unable to solve the following exercise:
Use the basic rules of algebra to simplify the following expression:
$$abfrac{1}{a}b^2cb^{-3}$$
Within the chapter of the book in question the author has covered:
- Associative, commutative and distributive properties of an equation
- Expanding brackets
- Factoring
- Quadratic factoring
- Completing the square
The solution in the answers section is simply "$c$". The equation simplifies to $c$. I cannot for the life of me see how. The solution provided does not give the steps in between, only the final solution $c$.
How can one arrive at $c$ with all the steps in between?
algebra-precalculus
algebra-precalculus
edited Nov 20 '18 at 19:08
Robert Howard
1,9161822
1,9161822
asked Nov 20 '18 at 16:31
Doug Fir
2057
2057
1
My +1 for good presentation of the context.
– Yves Daoust
Nov 20 '18 at 17:12
The global exponent of $a$ is $1-1$, that of $b$, $1+2-3$ and that of $c$ is $1$.
– Yves Daoust
Nov 20 '18 at 17:13
1
Here's a really helpful tutorial for MathJax formatting: math.meta.stackexchange.com/questions/5020/…. It's pretty easy to pick up!
– Robert Howard
Nov 20 '18 at 19:24
add a comment |
1
My +1 for good presentation of the context.
– Yves Daoust
Nov 20 '18 at 17:12
The global exponent of $a$ is $1-1$, that of $b$, $1+2-3$ and that of $c$ is $1$.
– Yves Daoust
Nov 20 '18 at 17:13
1
Here's a really helpful tutorial for MathJax formatting: math.meta.stackexchange.com/questions/5020/…. It's pretty easy to pick up!
– Robert Howard
Nov 20 '18 at 19:24
1
1
My +1 for good presentation of the context.
– Yves Daoust
Nov 20 '18 at 17:12
My +1 for good presentation of the context.
– Yves Daoust
Nov 20 '18 at 17:12
The global exponent of $a$ is $1-1$, that of $b$, $1+2-3$ and that of $c$ is $1$.
– Yves Daoust
Nov 20 '18 at 17:13
The global exponent of $a$ is $1-1$, that of $b$, $1+2-3$ and that of $c$ is $1$.
– Yves Daoust
Nov 20 '18 at 17:13
1
1
Here's a really helpful tutorial for MathJax formatting: math.meta.stackexchange.com/questions/5020/…. It's pretty easy to pick up!
– Robert Howard
Nov 20 '18 at 19:24
Here's a really helpful tutorial for MathJax formatting: math.meta.stackexchange.com/questions/5020/…. It's pretty easy to pick up!
– Robert Howard
Nov 20 '18 at 19:24
add a comment |
4 Answers
4
active
oldest
votes
First off, associativity means we don't need parentheses, which is good, because there are none given to us. Now, let's use the definition of exponents to get
$$
abfrac1abbcfrac1bfrac1bfrac1b
$$
Then we use commutativity to arrange things alphabetically. This gives us
$$
afrac1abbbfrac1bfrac1bfrac1bc
$$
The definition of fraction gives $afrac1a=1$ (and similarly for $b$). We get
$$
1cdot1cdot1cdot1cdot c
$$
And finally, by definition of $1$, this simplifies to $c$.
Thank you for the crystal clear answer. Deleting this comment in a few minutes...
– Doug Fir
Nov 20 '18 at 16:46
2
@DougFir, it's fine to leave your comment.
– Decaf-Math
Nov 20 '18 at 16:49
I find the use of "alphabetically" in a mathematical context weirdly funny. +1
– DreamConspiracy
Nov 21 '18 at 9:36
add a comment |
First, note that $ab frac{1}{a} = b$ and then substituting that into the equation we get $bb^2cb^{-3}$ so now we collect all the $b$ terms and the cancel leaving us with $c$ as the simplified expression.
add a comment |
By commutativity and associativity we can rearrange the expression as
$$left(afrac1aright)cdot(bb^2b^{-3})cdot c$$
the first term is clearly $1$. The second term is also $1$ because of how you add powers in a product: indeed
$$bb^2b^{-3}=b^{1+2-3}=b^0=1$$ So all you are left with is $c$
add a comment |
All that is needed here from the chapter in question are the associative and commutative properties of multiplication. The expression $abfrac{1}{a}b^2cb^{-3}$ can be re-arranged with commutativity to $afrac{1}{a}bb^2b^{-3}c$, and then this expression can be grouped into $(afrac{1}{a})(bb^2b^{-3})(c)$ with associativity. Those first two groups are both equal to $1$ (assuming of course none of the variables are $0$), and so you will be left with $c$. If this symbolic manipulation is still confusing, try substituting some values in for those variables! Try $a=2$, $b=3$, and $c=5$.
add a comment |
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4 Answers
4
active
oldest
votes
4 Answers
4
active
oldest
votes
active
oldest
votes
active
oldest
votes
First off, associativity means we don't need parentheses, which is good, because there are none given to us. Now, let's use the definition of exponents to get
$$
abfrac1abbcfrac1bfrac1bfrac1b
$$
Then we use commutativity to arrange things alphabetically. This gives us
$$
afrac1abbbfrac1bfrac1bfrac1bc
$$
The definition of fraction gives $afrac1a=1$ (and similarly for $b$). We get
$$
1cdot1cdot1cdot1cdot c
$$
And finally, by definition of $1$, this simplifies to $c$.
Thank you for the crystal clear answer. Deleting this comment in a few minutes...
– Doug Fir
Nov 20 '18 at 16:46
2
@DougFir, it's fine to leave your comment.
– Decaf-Math
Nov 20 '18 at 16:49
I find the use of "alphabetically" in a mathematical context weirdly funny. +1
– DreamConspiracy
Nov 21 '18 at 9:36
add a comment |
First off, associativity means we don't need parentheses, which is good, because there are none given to us. Now, let's use the definition of exponents to get
$$
abfrac1abbcfrac1bfrac1bfrac1b
$$
Then we use commutativity to arrange things alphabetically. This gives us
$$
afrac1abbbfrac1bfrac1bfrac1bc
$$
The definition of fraction gives $afrac1a=1$ (and similarly for $b$). We get
$$
1cdot1cdot1cdot1cdot c
$$
And finally, by definition of $1$, this simplifies to $c$.
Thank you for the crystal clear answer. Deleting this comment in a few minutes...
– Doug Fir
Nov 20 '18 at 16:46
2
@DougFir, it's fine to leave your comment.
– Decaf-Math
Nov 20 '18 at 16:49
I find the use of "alphabetically" in a mathematical context weirdly funny. +1
– DreamConspiracy
Nov 21 '18 at 9:36
add a comment |
First off, associativity means we don't need parentheses, which is good, because there are none given to us. Now, let's use the definition of exponents to get
$$
abfrac1abbcfrac1bfrac1bfrac1b
$$
Then we use commutativity to arrange things alphabetically. This gives us
$$
afrac1abbbfrac1bfrac1bfrac1bc
$$
The definition of fraction gives $afrac1a=1$ (and similarly for $b$). We get
$$
1cdot1cdot1cdot1cdot c
$$
And finally, by definition of $1$, this simplifies to $c$.
First off, associativity means we don't need parentheses, which is good, because there are none given to us. Now, let's use the definition of exponents to get
$$
abfrac1abbcfrac1bfrac1bfrac1b
$$
Then we use commutativity to arrange things alphabetically. This gives us
$$
afrac1abbbfrac1bfrac1bfrac1bc
$$
The definition of fraction gives $afrac1a=1$ (and similarly for $b$). We get
$$
1cdot1cdot1cdot1cdot c
$$
And finally, by definition of $1$, this simplifies to $c$.
answered Nov 20 '18 at 16:37
Arthur
111k7105186
111k7105186
Thank you for the crystal clear answer. Deleting this comment in a few minutes...
– Doug Fir
Nov 20 '18 at 16:46
2
@DougFir, it's fine to leave your comment.
– Decaf-Math
Nov 20 '18 at 16:49
I find the use of "alphabetically" in a mathematical context weirdly funny. +1
– DreamConspiracy
Nov 21 '18 at 9:36
add a comment |
Thank you for the crystal clear answer. Deleting this comment in a few minutes...
– Doug Fir
Nov 20 '18 at 16:46
2
@DougFir, it's fine to leave your comment.
– Decaf-Math
Nov 20 '18 at 16:49
I find the use of "alphabetically" in a mathematical context weirdly funny. +1
– DreamConspiracy
Nov 21 '18 at 9:36
Thank you for the crystal clear answer. Deleting this comment in a few minutes...
– Doug Fir
Nov 20 '18 at 16:46
Thank you for the crystal clear answer. Deleting this comment in a few minutes...
– Doug Fir
Nov 20 '18 at 16:46
2
2
@DougFir, it's fine to leave your comment.
– Decaf-Math
Nov 20 '18 at 16:49
@DougFir, it's fine to leave your comment.
– Decaf-Math
Nov 20 '18 at 16:49
I find the use of "alphabetically" in a mathematical context weirdly funny. +1
– DreamConspiracy
Nov 21 '18 at 9:36
I find the use of "alphabetically" in a mathematical context weirdly funny. +1
– DreamConspiracy
Nov 21 '18 at 9:36
add a comment |
First, note that $ab frac{1}{a} = b$ and then substituting that into the equation we get $bb^2cb^{-3}$ so now we collect all the $b$ terms and the cancel leaving us with $c$ as the simplified expression.
add a comment |
First, note that $ab frac{1}{a} = b$ and then substituting that into the equation we get $bb^2cb^{-3}$ so now we collect all the $b$ terms and the cancel leaving us with $c$ as the simplified expression.
add a comment |
First, note that $ab frac{1}{a} = b$ and then substituting that into the equation we get $bb^2cb^{-3}$ so now we collect all the $b$ terms and the cancel leaving us with $c$ as the simplified expression.
First, note that $ab frac{1}{a} = b$ and then substituting that into the equation we get $bb^2cb^{-3}$ so now we collect all the $b$ terms and the cancel leaving us with $c$ as the simplified expression.
answered Nov 20 '18 at 16:34
CyclotomicField
2,1921313
2,1921313
add a comment |
add a comment |
By commutativity and associativity we can rearrange the expression as
$$left(afrac1aright)cdot(bb^2b^{-3})cdot c$$
the first term is clearly $1$. The second term is also $1$ because of how you add powers in a product: indeed
$$bb^2b^{-3}=b^{1+2-3}=b^0=1$$ So all you are left with is $c$
add a comment |
By commutativity and associativity we can rearrange the expression as
$$left(afrac1aright)cdot(bb^2b^{-3})cdot c$$
the first term is clearly $1$. The second term is also $1$ because of how you add powers in a product: indeed
$$bb^2b^{-3}=b^{1+2-3}=b^0=1$$ So all you are left with is $c$
add a comment |
By commutativity and associativity we can rearrange the expression as
$$left(afrac1aright)cdot(bb^2b^{-3})cdot c$$
the first term is clearly $1$. The second term is also $1$ because of how you add powers in a product: indeed
$$bb^2b^{-3}=b^{1+2-3}=b^0=1$$ So all you are left with is $c$
By commutativity and associativity we can rearrange the expression as
$$left(afrac1aright)cdot(bb^2b^{-3})cdot c$$
the first term is clearly $1$. The second term is also $1$ because of how you add powers in a product: indeed
$$bb^2b^{-3}=b^{1+2-3}=b^0=1$$ So all you are left with is $c$
answered Nov 20 '18 at 16:35
b00n heT
10.2k12134
10.2k12134
add a comment |
add a comment |
All that is needed here from the chapter in question are the associative and commutative properties of multiplication. The expression $abfrac{1}{a}b^2cb^{-3}$ can be re-arranged with commutativity to $afrac{1}{a}bb^2b^{-3}c$, and then this expression can be grouped into $(afrac{1}{a})(bb^2b^{-3})(c)$ with associativity. Those first two groups are both equal to $1$ (assuming of course none of the variables are $0$), and so you will be left with $c$. If this symbolic manipulation is still confusing, try substituting some values in for those variables! Try $a=2$, $b=3$, and $c=5$.
add a comment |
All that is needed here from the chapter in question are the associative and commutative properties of multiplication. The expression $abfrac{1}{a}b^2cb^{-3}$ can be re-arranged with commutativity to $afrac{1}{a}bb^2b^{-3}c$, and then this expression can be grouped into $(afrac{1}{a})(bb^2b^{-3})(c)$ with associativity. Those first two groups are both equal to $1$ (assuming of course none of the variables are $0$), and so you will be left with $c$. If this symbolic manipulation is still confusing, try substituting some values in for those variables! Try $a=2$, $b=3$, and $c=5$.
add a comment |
All that is needed here from the chapter in question are the associative and commutative properties of multiplication. The expression $abfrac{1}{a}b^2cb^{-3}$ can be re-arranged with commutativity to $afrac{1}{a}bb^2b^{-3}c$, and then this expression can be grouped into $(afrac{1}{a})(bb^2b^{-3})(c)$ with associativity. Those first two groups are both equal to $1$ (assuming of course none of the variables are $0$), and so you will be left with $c$. If this symbolic manipulation is still confusing, try substituting some values in for those variables! Try $a=2$, $b=3$, and $c=5$.
All that is needed here from the chapter in question are the associative and commutative properties of multiplication. The expression $abfrac{1}{a}b^2cb^{-3}$ can be re-arranged with commutativity to $afrac{1}{a}bb^2b^{-3}c$, and then this expression can be grouped into $(afrac{1}{a})(bb^2b^{-3})(c)$ with associativity. Those first two groups are both equal to $1$ (assuming of course none of the variables are $0$), and so you will be left with $c$. If this symbolic manipulation is still confusing, try substituting some values in for those variables! Try $a=2$, $b=3$, and $c=5$.
answered Nov 20 '18 at 16:36
Valborg
111
111
add a comment |
add a comment |
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1
My +1 for good presentation of the context.
– Yves Daoust
Nov 20 '18 at 17:12
The global exponent of $a$ is $1-1$, that of $b$, $1+2-3$ and that of $c$ is $1$.
– Yves Daoust
Nov 20 '18 at 17:13
1
Here's a really helpful tutorial for MathJax formatting: math.meta.stackexchange.com/questions/5020/…. It's pretty easy to pick up!
– Robert Howard
Nov 20 '18 at 19:24