作业帮(1)2x+3y=16 3x-2y=11 (2）3x-4y=1 5x-6y=3
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
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)=11,2(x-y)+5(x+y)=27
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5(x-y)/x+y-x+y/2(x-y)
3分之2(X-Y)-4分之X+Y=-1,6(X+Y)-4(2X-Y)=16
解方程组：2(x-y)/3-x+y/4=-1 ,6(x+y)-4(2x-y)=16
(3x-y)^2+(3x+y)(3x-y),x=1,y=-2
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