Question

Factor by grouping.

3x2 + 7x – 6

A. (3x – 2)(x – 3)
B. (3x – 2)(x + 3)
C. (x + 3)(3x + 2)
D. (3x + 2)(x – 3)

Answer 1

I've eliminated A. and C.... then I got stuck

Answer 2

to do factor by grouping of the standard quadratic expression,\( ax^2+bx+c\), we need 2 numbers whose sum is 'b' and product = ac
for your Question,
can you find 2 numbers whose sum =7 and product = -6*3=-18 ?

Answer 3

B. (3x-2)(x+3)
=\[3x ^{2}+9x-2x-6\]

D. (3x+2)(x-3)
=\[3x ^{2}-9x+2x-6\]

so which one would give you +7x ?

Answer 4

I'm sooooo confused >.<

Answer 5

whats 9x-2x =... ?

Answer 6

7x

Answer 7

so B is the answer, because answer D would give you -7x

Answer 8

Since this is a multiple choice question, if you don't know how to factor to get the answer. Do it backward by multiply the answer out and see which one match your question.

Answer 9

Oooh, I see..thank you.