已知:x+y=2,求(x+y)²(2x+2y)²(3x+3y)²的值
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x²+x*y=-1,x*y+y²=2,试求2x²-x*y-3y²的值
已知x-3y=0,求(x²-2xy+y²/x-y)-2y的值
(1)已知x+y=6,x²-y²=5,求x-y的值(2)若x+y=3,x²+y²
已知方程组2x-y=10,x+2y=11,求(2x-y)³-(2x-y)²(x-3y)的值
已知x-3y=0,求2x+y/x²-2xy ×(x-y)的值
已知x+3y=0,求x³+3x²y-2x-6y的值.
已知方程组{2x+y=6,x-3y=1,不解方程组,求7y(x-3y)²-(3y-x)²的值.
已知x-y=3,求代数式(x+y)(x-y)+(x-y)²-(2xy-2y)²的值
已知x-3y=0,y≠0,求x²-2xy+y²分之2x+y×(x-y)的值