Question

simplify y^(-2/5)(y^(-8/5)+y^(17/5))

Answer 1

You should use the law of the exponents. http://www.mathsisfun.com/algebra/exponent-laws.html
\[y ^{-2/5} (y^{-8/5} + y^{17/5})\]
\[ =y^{(-2 + (-8)) / 5} + y^{(-2 + 17)/ 5}\]
\[= y^{-10/5} + y^{15/5}\]
Then just cancel the terms and simplify the expression.

Answer 2

You just simplify
\[y^{-10/5} \] to \[y^{-2}\] and similarly for the other term. That should do it.