提公因式：已知2x+y=6 x-3y=1 ,求7y(x-3y)²-2(3y-x)³的值.

提公因式：已知2x+y=6 x-3y=1 ,求7y(x-3y)²-2(3y-x)³的值.
提公因式：已知2x+y=6 x-3y=1 ,求7y(x-3y)²-2(3y-x)³的值.

提公因式：已知2x+y=6 x-3y=1 ,求7y(x-3y)²-2(3y-x)³的值.
7y(x-3y)²-2(3y-x)³
=7y(x-3y)²+2(x-3y)³
=(x-3y)²(7y+2x-6y)
=(x-3y)²(2x+y)
=1²*6
=6