已知方程组2x-y=10,x+2y=11,求(2x-y)³-(2x-y)²(x-3y)的值
问题描述:
已知方程组2x-y=10,x+2y=11,求(2x-y)³-(2x-y)²(x-3y)的值
答
(2x-y)³-(2x-y)²(x-3y)
=(2x-y)²[(2x-y)-(x-3y)]
=(2x-y)²(x+2y)
=10²×11
=1100