5xy²-[3xy²-(4xy²-2x²y)]+2x²y-xy
-3(xy-2x²)-[y²-(5xy-4x²)+2xy]
计算:(xy-x²)×x-y/xy
3x²y+xy²-[2xy²-4x²y+(x²y-2xy²)
(2x²y-3xy²)-3(x²y-2xy²)+2(x²y-4xy
x-y/x²÷x²-2xy+y²/xy*(xy-x²)
已知(x+1)²+|y-1|=0,求2(xy-5xy²)-(3xy²-xy)得值
计算:x²+2xy+y²/xy-y².x²-2xy+y²/xy+y
计算 2xy[4x²y²-3y(xy+x²y)-xy²]
化简4xy-3y²-3x²+xy-3xy-2x²+x²-2y²
已知x:y=3:2,求(x²+3xy)/(xy+2xy)
X²+2xy+y²/xy乘x²-2xy+y²/xy+y²=
合并同类项:(2xy²+3xy²)-(6x²y-3xy²)