Разложи на множители 42am+32mu−24au−56m2
14m(3a-4m)-8u(3a-4m)=(3a-4m)(14m-8u)=2(3a-4m)(7m-4u)
6a(7m-4u)+8m(4u-7m)=(4u-7m)(6a+8m)