Question

What are the x-intercepts of the function f(x) = –2x2 – 3x + 20? (–4, 0) and five-halves five-halves and (4, 0) (–5, 0) and (2, 0) (–2, 0) and (5, 0)

Answer 1

(-4, 0) and (5/2, 0)

Explanation:

Answer 2

(-4, 0) and (5/2, 0)

Explanation:

f(x) = –2x2 – 3x + 20

factor using the diamond method

-2*20 = -40

so -8 * 5 = -40 and -8 + 5 = -3 so...

f(x) = -2x^2 - 8x + 5x + 20

f(x) = -2x (x + 4) + 5 *(x + 4)

f(x) = (-2x + 5)*(x + 4)

x-intercepts are x = 5/2 and x =-4

(-4, 0) and (5/2, 0)