5x+3y=36 3x+y=20

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 x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20 {(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20 4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6 （5x+3y)(3y-5x)-(4x-y)(4y+x)= 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 已知x/5=y/3,则(x/x+y)+(y/x-y)-(yxy/xxx-yxy) |x|=3 |y|=5 |x-y|=|x|+|y| 求 X+Y和 X-Y 等于多少 3x+3y+2x-2y=36 4x+4y-5x-5y=2 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 解方程组