Answer:
Two solutions:
x = 5 and x = -3
Step-by-step explanation:
Simplify:
x^{2} - 2x = 15
-15 -15
x^{2} - 2x -15 = 0
Find what numbers multiplied by eachother equal -15 and also add to -2:
-5 * 3 = -15
-5 + 3 = -2
Rewrite equation and put each expression equal to 0:
(x - 5)(x + 3) = 0
x - 5 = 0 x + 3 = 0
+5 +5 -3 -3
x = 5 x = -3