Question

How do I solve (3x + 5)^2 - 8(3x + 5) + 12 = 0? If u = 3x + 5

Answer 1

I got up to u^2 - 8u + 12 = 0

Answer 2

I don't know what to do next

Answer 3

use factorization for polynomials

Answer 4

first (for beginners) you can list out the factors of 12 (including the negative signs, since it's -8 in the middle).

Answer 5

I'm not sure. The closest is -4 and -3, isn't it?

Answer 6

like: 12= 1x12
2x6
etc. you do the rest

Answer 7

yes, but there are other factors of 12 too

Answer 8

-6 and -2?

Answer 9

bingo!

Answer 10

from there on, you could put the numbers into different brackets to get your answer.

Answer 11

so u = 6 or u = 2?

Answer 12

yes

Answer 13

Thanks!

Answer 14

no problem!

Answer 15

thx for the medal anyway