Does anyone know what to do here?

n=-5

Step-by-step explanation:

y^5*y^n= y^5+n when multiply , add exponents

y^5+n/y^2= y^(5+n)-2 divide, subtract exponents

y^(5-5-2) =y^-2

step-by-step explanation:

no, her answer is not correct.   we square the lengths of all sides and then determine whether the pythagorean theorem holds here:

9² + 15² = 306.   this is not equal to the square of the longest side ( that square being 395.   answer c is correct.