Question

Factor completely: 3ab(x + 1) − 2(x + 1)

Answer 1

@ivettef365 @whpalmer4

Answer 2

Please help!

Answer 3

look at what you have - are there common factors between the two terms?

Answer 4

3abx + 3ab?

Answer 5

^not the answer

Answer 6

no, how about (x+1)?

Answer 7

wait what? Im confused already...

Answer 8

it might be easier to see written this way:
(x+1)3ab +(x+1)(-2)

Answer 9

(I just reversed the order of the multiplications, which does not change the value)

Answer 10

isn't that the same as (x+1)(3ab-2)?

Answer 11

yesh

Answer 12

3abx - 2x)(3ab - 2?

Answer 13

I dont know what to do with the x....

Answer 14

no, (x+1)(3ab-2) is the complete factoring
or if you prefer (3ab-2)(x+1)

Answer 15

wait wha? :-?

Answer 16

you're just undoing the distributive property here...

instead of going from \((p + q)(r + s) = p(r+s) + q(r+s) \) you are going the other way and taking \(p(r+s) + q(r+s) = (p+q)(r+s)\)

Answer 17

oh ok

Answer 18

it's sometimes a little hard to see the opportunities to do this at first, because you're not used to going in that direction...

Answer 19

yeah...

Answer 20

there's a technique called factoring by grouping that uses this...

Answer 21

ok that makes sense now thx!

Answer 22

great! you're welcome!