2x²y-3(2xy-xy)-xy
-3(xy-2x²)-[y²-(5xy-4x²)+2xy]
已知x:y=3:2,求(x²+3xy)/(xy+2xy)
(xy-x^2)乘以(xy)/(x-y)
合并同类项:(2xy²+3xy²)-(6x²y-3xy²)
(3x²y-xy²+2xy)/二分之一xy
已知(x+1)²+|y-1|=0,求2(xy-5xy²)-(3xy²-xy)得值
(x-2xy)*(-xy+2y*y)-(3x*x-2xy)(x-9xy+6y*y)
3xy²-[xy-2(xy-3/2x²y)+3xy²]+3xy²,其中x=3,y
x^2-xy-6y^2+3xy+y+2
先化简,再求值 ⒈2(Xy+Xy)-3(Xy-xy)-4Xy,其中X=1,y=-1
x-y/x²÷x²-2xy+y²/xy*(xy-x²)
(2x²y-3xy²)-3(x²y-2xy²)+2(x²y-4xy