若x²-3=2-y²,则-3x²-3y²=
若【2x²-3y²-10y+5】²+根号x-2y,则x= y=
若x、y满足2x+y=6,x-3y=1,求7y(x-3y)²-2(3y-x)³的值
已知x,y满足x²+y²-4x+6y+13=0则(3x+y)²-(3x+y)(3x-y)的
若集合A={(x,y)|y=x²,x∊R},B={(x,y)|y=2x²+2x-3,x&
(1)已知x+y=6,x²-y²=5,求x-y的值(2)若x+y=3,x²+y²
已知x,y的值满足方程组x+2y=3,x-y=-2,求x/(x-y)²+x²-y²/(x+
化简后求值 [(x-2y)²+(x-2y)(x-2y)-2x(2x-y)]÷2x 其中x=2 y=3
2x²-3xy=y²=0(x,y不得o)求x/y+y/x
已知y-2x=0,求3x²-2y²/(x+y)(x-y)的值
已知x+3y=2,求代数式(x²-y²/x+y)-【2(x+y)】的值
先化简,再求值:(3x-y)²+(3x+y)(3x-y),其中x=1,y=-2
若x+y=1,x²+y²=3,求x^3+y^3