Question

Factor the trinomial below.

x² - 2x - 48
O A. (x - 12)(x + 4)
B. (x + 6)(x-8)
O C. (x+12)(x - 4)
O D. (x-6)(x+8)

Answer 1

B

Explanation:

yes, we need two numbers that multiplied with each other results in -48.

that means already that one of them has to be positive and the other negative.

that gives us (with all +/- alternating sign combinations)

2 and 24

3 and 16

4 and 12

6 and 8

to pick from there we see that the "middle" term is -2x.

that means that the absolute value of the negative number has to be 2 more than the positive number (so that when adding the intermediate multiplication terms we end up with -2x).

the only choice is therefore 6 and -8.

and that makes B the right answer.