Question

Determine the zeros of each function by factoring:

a) f(x)=-2x^2-5x+12

b) f(x)=2x^2-3x-2

Answer 1

a) f(x) = -2x² - 5x + 12
0 = -2x² - 5x + 12
0 = -2x² - 8x + 3x + 12
0 = -2x(x+4) + 3(x+4)
0 = (-2x+3) + (x+4)
x = 3/2, x = -4

b) f(x) = 2x² - 3x - 2
0 = 2x² - 3x - 2
0 = 2x² - 4x + x - 2
0 = 2x(x-2) + 1(x-2)
0 = (2x+1)(x-2)
x = 2, x = -1/2