Question

Solve x2 − 7x = −12. (6 points) x = 6 and x = −2 x = 4 and x = 3 x = 2 and x = 6 x = −4 and x = −3

Answer 1

Answer: Choice B. x = 4 and x = 3

Work Shown:

x^2 - 7x = -12

x^2 - 7x + 12 = 0

(x - 3)(x - 4) = 0 ... see note below

x - 3 = 0 or x - 4 = 0

x = 3 or x = 4

Note: we're looking for two numbers that multiply to 12 and add to -7. Those two numbers are -3 and -4, so that's where the factorization (x-3)(x-4) comes in. After this step, you set each factor equal to zero and solve for x.

Answer 2

x=3 x=4

Explanation:

x^2 − 7x = −12

Add 12 to each side

x^2 - 7x +12 =0

Factor

What 2 numbers multiply to 12 and add to -7

-3*-4 = 12

-3+-4 = -7

(x-3)(x-4) =0

Using the zero product property

x-3 =0 x-4 =0

x=3 x=4