求解微分方程:y’²+2xy‘-x²-4y=0
一阶线性微分方程xy'-y-√x²+y²=0求通解
|x+2y+3|+(2x+y)²=0求x²-xy+y²
已知2x²-3y²=xy,(xy≠0),求值(4xy-x²)/(xy+2y²)的
x²-4y²/x²+2xy+y²÷x+2y/2x²+2xy
x²+y²+4x-8y+20=0,求分式x²-y²/xy的值
x²+y²+4x-8y+20=0,求(x²-y²)÷xy的解
已知X²-5XY+6Y²=0,求(X²+3XY)\2Y²的值
已知2x+3y=0,求代数式1.5x+4y/3x-2y 2.x²+xy-y²/x²-xy+
已知x²-4x+4=0,2y²+12y+18=0,求代数式9x²-12xy+4y²
已知(4X-2Y-1)²+根号xy-2=0,求4x²y²+xy²的值
方程组{x²+y²=10(1)x²-3xy+2y²=0(2)怎么解
设A=2x²-3xy+y²-x+2y,B=4x²-6xy+2y²+3x-y.若x