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

User Alain Boudard
by
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1 Answer

9 votes
9 votes

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.