well, I've got some problems that I can't solve, I'm doing the work all the day but I just can't solve those... I would appreciate your help

even if you can help just in one...

by the way I need it for wednesday so it's pretty urgent...

formula: ax^2+bx+c(trinom)

1.

6x^3+x^2-x+12x^2+2x-2

2.

30x^3-15x^2-14x^2+7x-4x+2

prove:

(7a-8)^2+2(7a-8)(11-7a)+(11-7a)^2=9

(11a+5)^2-2(11a+5)(11a-15)+(11a-15)^2=400

prove that:

(n^2+2n)(n^2-1)

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24

and last one:

given:

a+b=5

ab=3

How much is:

a^2+b^2

a^2b+ab^2

a^3b+ab^3

Thanks a lot for everyone who can help, even one of all these...