已知(X+Y)²=18,(X-Y)²=6,分别求X²+Y²及X²=3X
已知x+y=1,xy=-二分之一,求x(x+y)(x-y)-x(x+y)²
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+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+
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y
已知x²-y²=12,x+y=6,求x,y的值
(1)已知x+y=6,x²-y²=5,求x-y的值(2)若x+y=3,x²+y²
已知实数x, y满足x²+y²-2x+6y+10=0,求y∧-x.
已知x²+4y²-6x+8y+13=0,求x-y/x+y的值.
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
已知x,y满足x²+y²-4x+6y+13=0则(3x+y)²-(3x+y)(3x-y)的