
Brandon E.
asked 10/14/16(x^7a)^a-b / (x^3a)^a-2b
Expand and simplify the following powers. Give all of the answers in terms of positive exponents.
(x^7a)^a-b / (x^3a)^a-2b
Please help, and explain on how to get the answer. I've spent a long time trying to figure this out
Thanks.
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1 Expert Answer
An expression of the form (xm)n can be re-written as xmn
Therefore we have
x7a²-7ab ÷ x3a²-6ab
When we divide like bases, we subtract the exponents. Here, we have a common base of x.
So we have
x7a² - 7ab - (3a²-6ab)
= x4a²-ab
or x4a²/xab
Brandon E.
Thanks for the response. I'm still confused though, lol.
Why did the 7a get squared, and why did a-b become ab, where did the 2b go?
I'm learning this through an online course so it's mostly self taught so sorry if some of my questions don't make sense.
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10/14/16

Michael A.
tutor
No problem, Brandon. We welcome your questions, as that is how we all learn. We get 7a² because when the exponent is outside of the parenthesis, you multiply it times whatever exponent is within the parenthesis.
(x7a)a-b becomes x7a(a - b)
We have to distribute the 7a thru the parenthesis.
7a(a - b) = 7a² - 7ab
So we can re-write the numerator as x7a² - 7ab
Please do not hesitate to ask if you have any additional questions.
Thank you.
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10/15/16
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Mark M.
10/14/16