Question

Select the correct answer.

Which ordered pair represents a point where the graph of f(x) = (x - 1)(x2 + x - 20) crosses the x-axls?
(-1,0)
(-5,0)
(-4,0)
(20,0)

Answer 1

(-5,0) is the answer

Answer 2

(-5, 0)

Explanation:

f(x) = (x - 1)(x2 + x - 20) = 0

x - 1 = 0

x = 1

x^2 + x - 20 = (x + 5)(x - 4)

x + 5 = 0; x - 4 = 0

x = -5; x = 4

Answer: (-5, 0)