Разложи на многочлен; ; a) mx+my+6x+6y b) 9x-ay+9y+ax c) 7a-7b+an-bn d) 1-bx-x+b

a) mx+my+6x+6y = m(x+y)+6(x+y)=(m+6)(x+y)
b) 9x-ay+9y+ax = ?
c) 7a-7b+an-bn = 7(a-b)+n(a-b) = (7+n)(a-b)
d) 1-bx-x+b  = -(-1+x)-b(x-1) = -(-1+x)(1+b)