先化简,再求值 (x²-y²/xy)²÷(x+y)²*(x/x-y)²
先化简,再求值,先化简,再求值,【1/(x-y)】-【1/(x+y)】/【xy²/(x²-y
先化简,后求值[(x-y)²-(x+y)]/(2xy) 先化简,后求值[(x-y)²-(x+y)]/
先化简,再求值:{xy(x²-3y)+3xy²}(-2xy)+x³y²(2x-y
先化简在求值(x+y)²-(x-y)(x+y)-(xy)²÷(xy),其中x,y是方程组『3x+2y
先化简,再求值,x分之x-y÷(x-x分之2xy-y²)其中x=2,y=-1
化简求值[1-(2x/x+y)]÷ (x²-2xy+y²/3x+3y)+(x²+xy/x&
化简求值:x-y/x²-2xy+y²-xy+y²/x²-y²,其中(x
先化简,再求值:3x²—[2x²y—(xy—x²)]+4x²y,其中x=—1,y
先化简在求值【(2y-3x)(-3x-2y)-(-3x+y)²-2y/3(3x-y+3xy²)】÷(
x²/xy-x/y
1.化简求值:(x+y)(x-y)-(x-y)²-6x²y÷2y+(2xy)²÷(-4xy
x-y/x²÷x²-2xy+y²/xy*(xy-x²)