化简求值:(1)2x²-y²+(2y²-x²)-(x²+2y²
化简求值 【2x²-(x+y)(x-y)][(x+y-1)(x-y+1)+1-2y],其中x=-1,y=-2
化简求值:(1)2x²-y²+(2y²-x²)-(x²+2y²
化简求值:x-y/x²-2xy+y²-xy+y²/x²-y²,其中(x
先化简再求值:(x-2y)²-(x+2y)(x-2y)-(x-3y)(x-y).其中x²+9y
(x+y)(x-2y)(x²-4y²) 其中x=8 y=-8 化简求值
化简求值:(x+2y)²-(x+y)(x-y),其中x=-2,y=二分之一
一、 化简求值1 (x-2-(12)/(x+2))/(4-x)/(x+2)2【(x-y)²+(x+y)(x-y
先化简,在求值:(x-y)²+(3x-2y)(2x+y)-x(6x-y)
化简求值[1-(2x/x+y)]÷ (x²-2xy+y²/3x+3y)+(x²+xy/x&
先化简,后求值[(x-y)²-(x+y)]/(2xy) 先化简,后求值[(x-y)²-(x+y)]/
化简求值3x[xy-2x(y-2x)]+3y(x²-y²),其中x=-1,y=2
化简求值:(x+y)(x-y)+(x-y)²-(6x²y-2xy²)÷2y,其中x=-2,