Question

What is the value of z so that –3 and 3 are both solutions of x² + z = 25? 22 16 41 9

Answer 1

Notice that:

$(3)^2=(-3)^2=9.$

Substituting x²=9, we get the following equation:

$9+z=25.$

Solving for z, we get:

$\begin{gathered} z=25-9, \\ z=16. \end{gathered}$

Answer:

$16.$