I actually really need help with this >.< I don't know if i'll even get how to do these after someone has explained them to me.

RainbowPanda
Sep 4, 2018

#1**+2 **

I assume we want to factor, RP.....so

1) 56b^3 + 7b^2 + 168b + 21

We need to do something called "factor by grouping"....there isn't a standard proceedure, necessarily, but here's one way we can proceed

Take the GCF out of 56b^3 + 7b^2 = 7b^2

Take the GCF out of 168b + 21 = 21

Write the expression back like this :

7b^2 (8b + 1) + 21 (8b + 1) ......note that (8b + 1) is common...so write it...and then follow it with the other two terms as a second factor....so we have

(8b + 1) ( 7b^2 + 21) .....note....in the second factor, we can take out a "7"...so we have...

(8b + 1) (b^2 + 3) *7 =

7(8b + 1) (b^2 + 3)

CPhill
Sep 4, 2018

#2**+2 **

2) 294n^3 + 343n^2 + 126n + 147

This one isn't as obvious....

Take out the GCF between 294n^3 and 343n^2 = 49n^2

Take out the GCF between 126 and 147 = 21

So we have

49n^2 [ 6n + 7 ] + 21 [ 6n + 7 ]

[6n + 7 ] [ 49n^2 + 21] note....in the second factor...we can take out a "7" and we have

[6n + 7] [ 7n^2 + 3] *7

7 [ 6n + 7 ] [7n^2 + 3 ]

CPhill
Sep 4, 2018