SOLUTION: Actually I wanted to favtorize: {{{15x^2-22x+8}}} So I multiplied 8 with 15 and got 120. The factors came as {{{-10}}} and {{{-12}}} Then I split the {{{22x}}} into these 2 num

Algebra ->  Distributive-associative-commutative-properties -> SOLUTION: Actually I wanted to favtorize: {{{15x^2-22x+8}}} So I multiplied 8 with 15 and got 120. The factors came as {{{-10}}} and {{{-12}}} Then I split the {{{22x}}} into these 2 num      Log On


   

Question 252544: Actually I wanted to favtorize:
15x%5E2-22x%2B8
So I multiplied 8 with 15 and got 120.
The factors came as -10 and -12
Then I split the 22x into these 2 numbers, so I got:
15x%5E2-10x-12x%2B8
Then what do I do next? Please help I have no clue!
Found 4 solutions by JimboP1977, Alan3354, Edwin McCravy, kensson:
Answer by JimboP1977(311) About Me  (Show Source):
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
15x%5E2-22x%2B8
-----------------
It's a trial and error thing. The 1st term, 15, can be:
1*15 or 3*5
The last term, 8, can be 1*8 or 2*4. It's +8, so the signs are the same.
Start with 1 and 15, ignore the sign but try to get 22 for the middle term:
(x - 1)*(15x - 8) --> 23x NG
(3x - 1)*(5x - 8) --> 29x NG
------------------------------
(x - 2)*(15x - 4) --> 34x NG
(3x - 2)*(5x - 4) --> 22x That's it. The 22x is negative, so it's factored.
------------------------------------
The best approach is to use the quadratic equation, but students are usually subjected to factoring before learning the quadratic equation.

Answer by Edwin McCravy(20086) About Me  (Show Source):
You can put this solution on YOUR website!

Split it into a red half and a black half

red%2815x%5E2-10x%29-12x%2B8

Factor red%285x%29 out of the red half, and
factor -4 out of the black half.
Don't forget that since you're taking a negative
out of the %22%22%2B8 you get -2 not %22%22%2B2.

red%285x%283x-2%29%29-4%283x-2%29

Do some re-coloring:

5xgreen%28%283x-2%29%29-4green%28%283x-2%29%29

Take out the green parentheses, and that leaves the black
5x and the black -4 in another parentheses:

green%28%283x-2%29%29%285x-4%29

That's it!

Edwin

Answer by kensson(21) About Me  (Show Source):
You can put this solution on YOUR website!
Great start!
You need to factorize the first pair of terms and the second before joining them together:
5x(3x-2) - 4(3x-2) = (5x-2)(3x-2)