Answer:
x = -3 or x = 5
Step-by-step explanation:
Solve: x^2 -2x = 15
x^2 - 2x - 15 = 0
Use the Diamond method of factoring
-15 = 3* -5 and 3 - 5 = -2 so...
x^2 - 2x - 15 = x^2 - 5x + 3x - 15
x^2 - 2x - 15 = x *(x - 5) + 3*(x - 5)
x^2 - 2x - 15 = (x + 3)*(x - 5)
x^2 - 2x - 15 = (x + 3)*(x - 5) = 0
solve (x + 3 ) = 0 and (x - 5) = 0
x = -3 or x = 5
