Question

Solve x2 − 7x = −12.

a. x = 2 and x = 6
b. x = 6 and x = −2
c. x = −4 and x = −3
d. x = 4 and x = 3

Answer 1

x^2 - 7x = -12

Add 12 to both sides.

Doing so, we get x^2 - 7x +12 = 0.

We now factor the left side.

Doing so, we get (x - 3) (x - 4) = 0.

Set each factor to 0 and solve for x.

x - 3 = 0

x = 3

x - 4 = 0

x = 4

Answer: Choice d