来自董华春的问题
化简求值:3(x-y)-1/2(x+y)+3/4(x-y)²+3/2(x+y),其中x+y=2,x+y=-3.
化简求值:3(x-y)-1/2(x+y)+3/4(x-y)²+3/2(x+y),其中x+y=2,x+y=-3.
1回答
2020-10-02 14:16
化简求值:3(x-y)-1/2(x+y)+3/4(x-y)²+3/2(x+y),其中x+y=2,x+y=-3.
化简求值:3(x-y)-1/2(x+y)+3/4(x-y)²+3/2(x+y),其中x+y=2,x+y=-3.
3(x-y)-1/2(x+y)+3/4(x-y)²+3/2(x+y),x-y=2,x+y=-3.
=3(x-y)+(x+y)+3/4(x-y)²
=3*2-3+3/4*2²
=6