(3x²+2xy-½x)-(2x²-xy+xy)

-3(2x²-xy)+4(x²+xy-6) 因式分解x²-2xy-3x -3(xy-2x²)-[y²-(5xy-4x²)+2xy] 已知x:y=3:2,求(x²+3xy)/(xy+2xy) x-y/x²÷x²-2xy+y²/xy*（xy-x²） 3x-2xy-8-2x+6xy-x²+6、-x²+2xy-y²-3x²-2xy+ 合并同类项：(2xy²+3xy²)-(6x²y-3xy²) （3x²y-xy²+2xy)/二分之一xy 计算：(xy-x²)×x-y/xy （xy-x^2)乘以(xy)/(x-y) 已知(x+1)²+|y-1|=0,求2(xy-5xy²)-(3xy²-xy)得值 3x²y+xy²-[2xy²-4x²y+（x²y-2xy²）