a(6a+11b+4)+b(3b-1)-2
=6a²+11ab+3b²+4a-b-2
=(3a+b)(2a+3b)+4a-b-2
=(3a+b-1)(2a+3b+2)
x^2+2(a+b)x-3a^2+10ab-3b^2
=x^2+2(a+b)x+(a-3b)(-3a+b)
=[x-(a-3b)][x-(-3a+b)]
=(x-a+3b)(x+3a-b)