Question

Simplify the following rational expression.

z^2-16z+64/z^2-64

Which values of Z make the expression undefined? Choose all that apply.

z=6
z=-8
z=-4
z=8

Answer 1

z=-8 and z=8

Explanation:

A rational expression is undefined when its denominator is equal to zero, so our expression is undefined when
`z^2-64=0`. Solving for z, we get

`z^2=64\\√(z^2)=\pm√(64)\\ z=\pm8`