CPM Homework Help : GC Problem 10-73

Mrs. Cassidy solved the problem $(w − 3)(w + 5) = 9$ 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.

$(w + 6)(w − 4) = 0$

Answer:

$w = −6, 4$