已知x²+2xy+y²\xy-y²÷A=xy+y²\x²-2xy+y&
x-y/x²÷x²-2xy+y²/xy*(xy-x²)
X²+2xy+y²/xy乘x²-2xy+y²/xy+y²=
已知x:y=3:2,求(x²+3xy)/(xy+2xy)
计算:(xy-x²)×x-y/xy
计算:x²+2xy+y²/xy-y².x²-2xy+y²/xy+y
已知x/y=3,求(x²+2xy-3xy²)/(x²-xy+y²)
已知:X+Y=-3,XY=2,X²Y+XY²
已知x²-7xy+12y²=0求x²-xy+y²/2xy的值
已知(x+1)²+|y-1|=0,求2(xy-5xy²)-(3xy²-xy)得值
已知实数xy满足x²﹢y²-xy+2x-y+1=0求xy
已知x+y=4.x-y=6.求代数式xy(y²+y)-y²(xy+2x)-3xy的值
x²/xy-x/y