(1)3xy³/x²y=( )/x (2)4/x-1=( )/(x-1)(x+1)
x(x-1)-(x平方-y)=-3,求x平方+y平方-2xy
化简 (x+y)(x²-xy+y²) ; 3(2x-1)(x+6)-5(x-3)(x+6)
1/x-1/y=4,求分式(3x+xy-3y)/(x-2xy-y)
|x+2|+(y-1/4)²=0,求2(x²y+xy)-3(x²y-xy)-4x²
(1).设A=2X²-3Xy+y²+X-3y,B=4X²-6xy+2y²+4X-
先化简,再求值:3x²—[2x²y—(xy—x²)]+4x²y,其中x=—1,y
(1)3xy³/x²y=( )/x (2)4/x-1=( )/(x-1)(x+1)
化简求值[1-(2x/x+y)]÷ (x²-2xy+y²/3x+3y)+(x²+xy/x&
通分计算:(1)2x-3/(x-1)(x-4) - x-2/(1-x)(4-x) (2)x平方-y平方/xy - xy-
当x=2,y=-1时,求代数式(x+y)(x-y)+(x-y)²-(x²-3xy)的值
2(x的平方y+xy)-3(x的平方y-xy)=4x的平方y 其中x=1 y=-1
化简求值:2(x的平方y+xy)-3(x平方y+xy)-4x平方y,其中x=-1,y=2