X-2Y/3 - X+2Y/2 =-1 ,X-2Y/4-X+2Y/5 =-1 等于?
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
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
设x>1,y>0,若x^y+x^-y=2根号2,则x^y-x^-y等于
x/4+2等于x,x=多少.y/5等于y-3,Y=多少
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
1、x(x-y)(x+y)-x(x+y)^2
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y
(3x-y)^2+(3x+y)(3x-y),x=1,y=-2
(x+2)(x+3) (x-4)(x+1) (y+4)(y-2) (y-5)(y-3)