б) 7a(a+b)-6(a+b)=(а+b)(7a-6)в) 3(xy-2)+2-xy=3(xy-2)-(xy-2)=(xy-2)(3-1)=2*(xy-2)г) 5bc+6b+5cd+6d = 5bc+5cd+6d+6b=5c(b+d)+6(b+d)=(b+d)(5c-6)
б) 7a(a+b)-6(a+b)=(а+b)(7a-6)
в) 3(xy-2)+2-xy=3(xy-2)-(xy-2)=(xy-2)(3-1)=2*(xy-2)
г) 5bc+6b+5cd+6d = 5bc+5cd+6d+6b=5c(b+d)+6(b+d)=(b+d)(5c-6)