3(x-1)=y-31 5(y-1)=3(x+5)
先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
(2x+y-1)(2x-y+1)-(3x+y)(3x-y),其中x=5分之1,
设变量xy满足 x+y-3 x-y+1 3x-y+5 z=x+y/x
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
3X+5y=2 x+y=1
3x-2y=1 4x-5y
x+y=3 x+2y=9 3/x+1=y y-x=3 y=2x-3 y-3x=1 2(x+1)-y=6 7x-5y=-9
化简求值(x+2y)^2-(2x+y)(2x-y)-5y(y-x) 其中 x=1/3 y= -1/2
7x-3y/5=5x-y/3-x+y/2 x-1/5=y+1/3
解方程组{(x-2)(y+3)=(x+1)(y-1) {(x+1)(y+1)=(x-1)(y+5)