(4x²y+5xy-7x)-(5x²y+4xy+x)求解
-3(xy-2x²)-[y²-(5xy-4x²)+2xy]
x^3y(-4y)^2+(-7xy)^2*(-xy)-5xy^3*(-3x)^2
计算:(xy-x²)×x-y/xy
x²/xy-x/y
已知x²+y²-2x+4y+5=0,求X^4-y^4/2x^2+xy-y²·2x-y/xy
若x²+y²=7,xy=-2,求5x²-3xy-4y²-11xy-7x²
已知x²+y²=7,xy=-2.那么5x²-3xy-4y²-11xy-7x
1.已知x²+y²+7 xy+-2求5x²-3xy-4y²-11xy-7x
已知X²+Y²=7,XY=-2,求代数式5X²-3XY-4Y²-11XY-7X&
已知x²-y²=-8,xy=-3,求5x²-3xy+4y²+11xy-7x
化简 3x²+4xy+y²-2xy-3y²+5x²+7;
化简3/(x²+2xy+y²)-4/(x²-2xy+y²)+5/(x²