The Power of a Power Rule

Question

Simplify. All variables represent nonzero real numbers.

-5y^4(y^5)^2 / 15y^7(y^2)^3

I got:

-5y^40 / 15y^42

Is this correct?

Answer 1

no. In the numberator, y^5 squared is y^10. That times y^4 is y^14
In the denominator, y^2 cubed is y^6, and that times y^7 is y^13

then y^14/y^13 is y

Answer 2

Thanks. See my other post for a comment.

Answer 3

Wow... this is all the way from 2009 and I'm commenting on this in 2016. Really scary...