Need Help with These Exponential Equations

**Reiper** · May 13th 2012, 02:22 PM

Hello there!
I recently enrolled in a high school math course needed to take a college course, but I was always dreadful at math, and this is a correspondence course with minimal student assistance.

I am having some difficulties, and would like help with two question

1)

(3x⁴*y⁵*z⁷)⁵___________
(-3x³*yz⁴)⁷

For this question I got
y¹⁸z⁷
_____
9x

However I think I am wrong. The next question I found even more confusing

2)

(x^a+b)^a-b
_________

(x^a-2b)^a+2b
for this one I got 1/-4 but again, i think I am very lose

**Prove It** · May 13th 2012, 05:25 PM

Originally Posted by Reiper

Hello there!
I recently enrolled in a high school math course needed to take a college course, but I was always dreadful at math, and this is a correspondence course with minimal student assistance.

I am having some difficulties, and would like help with two question

1)

(3x⁴*y⁵*z⁷)⁵___________
(-3x³*yz⁴)⁷

For this question I got
y¹⁸z⁷
_____
9x

However I think I am wrong. The next question I found even more confusing

2)

(x^a+b)^a-b
_________

(x^a-2b)^a+2b
for this one I got 1/-4 but again, i think I am very lose

You are close with the first, just remember that $\displaystyle \begin{align*} (-3)^7 = -3^7 \end{align*}$ , so your answer should be negated.

I'm afraid you're not even close with the second. You need to use the following: $\displaystyle \begin{align*} \left(a^p\right)^q = a^{pq} \end{align*}$ and $\displaystyle \begin{align*} \frac{a^{m}}{a^n} = a^{m - n} \end{align*}$

**Reiper** · May 14th 2012, 08:36 AM

(x^a+b)^a-b

so here is what I am not getting, why do you not just multiply the exponents? IE (a+b)(a-b) = (a²-b²)
and if I do (x^a+b) = (x^ax^b, then where do I go from there with the exponents outside the bracket?

could someone show me what step 2 and three of this question would look like?