7x²y-[6xy²-5(xy²+3/4x²y)-2/3xy²]-xy
-3(xy-2x²)-[y²-(5xy-4x²)+2xy]
计算:(xy-x²)×x-y/xy
合并同类项:(2xy²+3xy²)-(6x²y-3xy²)
3x²y+xy²-[2xy²-4x²y+(x²y-2xy²)
(2x²y-3xy²)-3(x²y-2xy²)+2(x²y-4xy
已知(x+1)²+|y-1|=0,求2(xy-5xy²)-(3xy²-xy)得值
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)
已知xy²=-6,求xy(x^3y^7-3x^2y^5-11.5y)的值
(3x²y-xy²+2xy)/二分之一xy
先化简,再求值:{xy(x²-3y)+3xy²}(-2xy)+x³y²(2x-y