CPM Homework Help : INT2 Problem 8-44

Jamila solves the quadratic equation $x^2 + 3x - 10 = 8$ (see her work below). When she checks her solutions, they do not make the equation true. However, Jamila cannot find her mistake. Explain her error and then solve the quadratic equation correctly.

$x^2 + 3x - 10 = 8$
$(x + 5)(x - 2) = 8$
$x + 5 = 8$ or $x - 2 = 8$
$x = 3$ or $x = 10$

Hint:

When solving a quadratic equation, it is important to set one side equal to zero.

Step:

$x^2 + 3x - 18 = 0$