# Math Help - Can Someone Correct Me?

1. ## Can Someone Correct Me?

a few problems I had to do for homework. Just wondering if someone could correct me?

Directions - Simplify Expressions with Rational Exponents

1. (8/27)^-2/3 = I got 9/4 for an answer

2. x^1/5 / x^3/10 = my answer.....X^1/10

3. (A^3 b^6)^1/3 = ab^2

4. (a^2/3 b^2)^6 (a^3 b^3)^1/3 = A^5b^13

5. (4c^5/3 / a^-1/4 b^5/6)^-3/2 = b^5/4 / 8c^5/2 a^3/8

confusing as heck to read. I could take pictures of the problems and answers like I did yesterday but someone told me not to do that i guess?

2. Originally Posted by fallenx33
a few problems I had to do for homework. Just wondering if someone could correct me?

Directions - Simplify Expressions with Rational Exponents

1. (8/27)^-2/3 = I got 9/4 for an answer

3. well. i know that number 3 is right. i'll have to do the others on a sheet of paper.

4. Originally Posted by fallenx33
2. x^1/5 / x^3/10 = my answer.....X^1/10 $x^{\frac{\color{red}-\color{black}1}{10}}$
$x^{\frac{1}{5}}\div x^{\frac{3}{10}}$

$=x^{\frac{1}{5}-\frac{3}{10}}$

$=x^{\frac{-1}{10}}$

5. k so #1 is right, #3 is right.....and #2 should be x^-1/10?

6. Originally Posted by fallenx33
1. (8/27)^-2/3 = I got 9/4 for an answer
Correct.

2. x^1/5 / x^3/10 = my answer.....X^1/10
Not quite.

$\frac{x^{1/5}}{x^{3/10}}$

$=x^{1/5-3/10}=x^{2/10-3/10}$

$=x^{-1/10}=\frac1{x^{1/10}}$

We could also write it as $\frac1{\sqrt[10]x},$ but I think the exponential form looks better in this case (and depending on what the assignment requires, you could probably just leave it at $x^{-1/10}$).

3. (A^3 b^6)^1/3 = ab^2
Correct.

4. (a^2/3 b^2)^6 (a^3 b^3)^1/3 = A^5b^13
Correct.

5. (4c^5/3 / a^-1/4 b^5/6)^-3/2 = b^5/4 / 8c^5/2 a^3/8
Correct, assuming the $b^{5/6}$ is supposed to be in the denominator.

Yes. I don't think you are following the normal order of operations here (at least, I did not interpret it that way). You should make liberal use of parentheses to eliminate ambiguity.

I could take pictures of the problems and answers like I did yesterday but someone told me not to do that i guess?
Pictures are usually a nuisance, but they are okay if that is the best you can do. I suggest becoming acquainted with $\text{\LaTeX}$ (LaTeX); for a quick tutorial, see this post.

7. Yes b^5/6 is in the denominator in #5

and I had X1/1^10 for #2 to begin with. Should I change my answer back?

8. change your answer, so you won't confuse yourself, and write down the wrong answer instead. I think its alright if you change it.

9. Originally Posted by fallenx33
and I had X1/1^10 for #2 to begin with. Should I change my answer back?
No, that is not correct under any reasonable interpretation that I can think of (but again, you are not using clear notation). Re-read my working.