Solve each quadratic equation. show your work 15. x2 + 3x = 10

X² + 3x = 10

Convert to standard form.
x² + 3x - 10 = 0

factor x² = x * x
factor -10 = 5 * -2

(x + 5) (x - 2) = 0
x(x -2) + 5(x-2) = 0
x² - 2x + 5x - 10 = 0
x² + 3x - 10 = 0

x + 5 = 0               x² + 3x = 10
x = -5               -5² + 3(-5) = 10
                              25 - 15 = 10
                                     10 = 10

x - 2 = 0            x² + 3x = 10
x = 2               2² + 3(2) = 10
                             4 + 6 = 10
                                 10 = 10

D. Opposite angles are congruent

Step-by-step explanation: