Question

Factor this expression completely. −3x − 12 A) 3(x + 4) B) 3(x − 4) C) −3(x + 4) D) −3(x − 4)

Answer 1

Answer:

C

Step-by-step explanation:

Look at the coefficients in the expression: -3 and 12.  The largest number that divides them both is 3.  That means you can factor out either a 3 or a negative 3.  Try 3.

3(-x - 4) is not on the list of answers.  Also, it's unusual to factor out a value that leaves a negative coefficient on x.

Try factoring out -3.

-3(x + 4) is answer choice C.

Bonus

Because this is a multiple-choice question without a "non of these" option, you can solve the problem by expanding--multiplying out--the answers!

A. 3(x + 4) = 3x + 12 ...nope, not it

B. 3(x - 4) = 3x -12 ...nope, not it

C. -3(x + 4) = -3x -12 ...bingo!