Question

What is the value of y^-5 and x^-3 for x = 2 and y = -4?

answers


A. 10/3



B.
128


C. -1/128



D.
-128

Answer 1

`a^(-n)=(1)/(a^n)\\\\x^(-3)=(1)/(x^3);\ y^(-5)=(1)/(y^5)\\\\(y^(-5))/(x^(-3))=(1)/(y^5):(1)/(x^3)=(1)/(y^5)\cdot(x^3)/(1)=(x^3)/(y^5)\\\\x=2;\ y=-4=-2^2\\\\(x^3)/(y^5)=(2^3)/((-2^2)^5)=(2^3)/(-2^(2\cdot5))=(2^3)/(-2^(10))=-(1)/(2^7)=\boxed{-(1)/(128)}\to\fbox{C.}`