Question

x^2+x-20=0

Answer 1

You factor it.

Factors of -20 are -4 and 5 which add up to one
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(x-4)(x+5) is the answer

Answer 2

After factoring, (x-4)(x+5) = 0.
Use the Zero Product Property to solve for x.
x-4 = 0 or x + 5 = 0
x = 4 or x = - 5 --> ANswer

Answer 3

^^ Directrix said.