3x-2y=17 3x+5y=-11

3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 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 {3x-2y=3,2x+2y=17 {4x-2y=14,5x+y=7 {x+3y=6,2x-3y=3 {2x+3y=11 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 换元法解方程组3/x+y+2/x-y=17/5 2/x+y-5/x-y=1 解方程组 {3(x+y)-4(x-y)=11 {2(x-y)+5(x+y)=27全过程、快 解方程组 {3(x+y)-4(x-y)=11 {2(x-y)+5(x+y)=27 已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 (3x+2y)+(5x-y)i=17-2i.求x与y 已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(