SOLUTION: Express as a single fraction: a^-2 + b^-3 1/a^2 + 1/b^3 = 1/a^2+b^3. This is not correct. Can I get help with my work? Thank you.

Algebra ->  Exponents-negative-and-fractional -> SOLUTION: Express as a single fraction: a^-2 + b^-3 1/a^2 + 1/b^3 = 1/a^2+b^3. This is not correct. Can I get help with my work? Thank you.      Log On


   

Question 804095: Express as a single fraction: a^-2 + b^-3
1/a^2 + 1/b^3 = 1/a^2+b^3.
This is not correct. Can I get help with my work?
Thank you.
Found 2 solutions by richwmiller, DrBeeee:
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
1/a^2 + 1/b^3
(a^2+b^3)/(a^2 b^3)

Answer by DrBeeee(684) About Me  (Show Source):
You can put this solution on YOUR website!
Your first step is correct, but you still have two fractions. You need to add them to get a single fraction.
Given:
(1) a%5E%28-2%29+%2B+b%5E%28-3%29 which converts to
(2) 1%2Fa%5E2+%2B+1%2Fb%5E3
Now you can choose a%5E2%2Ab%5E3 for the common denominator of the two fraction in (2) and get, by multiplying by %28a%5E2%2Ab%5E3%29%2F%28a%5E2%2Ab%5E3%29 and get
(3) b%5E3%2F%28a%5E2%2Ab%5E3%29+%2B+a%5E2%2F%28a%5E2%2Ab%5E3%29 or
(4) %28b%5E3+%2B+a%5E2%29%2F%28a%5E2%2Ab%5E3%29
Answer: the single fraction of (4)