x+2y=-5&2x-5y=-1.3x=5y&2x-3y=-1 .2x+4y=11&3y-2y=3 .2x+3y=14&
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
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
6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5
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)+...-(
已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y
x+2y=-5&2x-5y=-1.3x=5y&2x-3y=-1 .2x+4y=11&3y-2y=3 .2x+3y=14&
数学题……555{(3x+y)(3x-y)-(x-5y)(5x-y)-(x-2y)²÷(-4x),x=-2.y
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai
5(x+y-2)=3-y