40A^2 + 31AB+6b^2

Question

dont get it. 

Answer 1

40a²+31ab+6b²

you have to factor this into the product of two binomials, each with two variables, a and b

40*6=2*2*2*5*2*3

rearrange the factors

(2*2*2*2)*(3*5)=16*15 and 16+15=31, the coefficient of the middle term

in other words, 40=8*5, 6=2*3, the 8 multiplies the 2 and the 5 multiplies the 3

(8a    )(5a    ) so far...

(8a   3b)(5a   2b) so far...

(8a+3b)(5a+2b) is the answer

FOIL it out to see that it equals the original polynomial