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.
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)
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 ]