CPM Homework Help : CCG Problem 10-90

Mrs. Cassidy solved the problem $\left(w-3\right)\left(w+5\right)=9$ and got $w = 3$ and $w=-5$ . Is she correct? If so, show how you know. If not, show how you know and find the correct solution.

Hint:

Substitute the solutions into the equation. Are the answers correct?

Step 1:

Rewrite the equation.

$w^2+2w-15=9$
$w^2+2w-24=0$

Step 2:

Factor the equation.

$\left(w+6\right)\left(w-4\right)=0$

Answer:

$w=-6,4$