Question

Solve by factoring or finding square roots
X^2-3x-4=0

A. 2, -2
B. -4. -1
C. 2, -1
D. 4, -1

Answer 1

(x + 4 ) (x - 1)
check by foiling:
First: x * x = x^2
Outter: x * -1= -x
Inner: 4 * x = 4x
Last: 4 * -1= -4
add like terms: 4x -x = 3x
so it works

now set binomials to equal 0:

x + 4 = 0
subtract 4
x= -4

x -1 =0
add 1
x = 1

x= -4, 1