Question

Solve the equation by factoring, show all work.

x^2+8x-20=0

Answer 1

hi there,
first look at c, which is -20. what 2 numbers, when multiplied, equal -20 and add up to positive 8?

well, 10 x -2 = -20, and 10-2 = positive 8,
so it would become

(x+10)(x-2) = 0

set both of these equal to 0 and solve, so

x+10 = 0
subtract ten from both sides,
x = -10

AND

x-2 = 0
add 2 to both sides, so
x = 2

your answers are x = -10 AND x = 2
:D