Question

Factor the equation below.
f(x) = x2 + x - 20

Answer 1

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

Explanation:

First muliply the coefficient of the xsquared with the constant, in this case 1 × -20 = -20. Then figure out two factors of -20 that equal the coefficient of the stand-alone x when added together. In this case, that coefficient is 1. Factors of -20 that add to 1 are 5 and -4. Now simply take each of those numbers and shove them into parenthesis with an x.

Answer 2

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

Explanation:

Key skills used in this problem: Quadratic equations, factoring

1) The equation x^2 + x - 20 is factorable (meaning it can be facttored easily)

2) We need to find factors of -20 that add up to 1. This is because our ac (a term times the c term) is -20 and our b term (the coefficient for +x) is 1.

3) The two factors would be 5 and -4.

4) So it would be (x + 5)(x - 4) when factored

Hope you understood and have a nice day!! :D