方程2x-y=1,y-4=x,5x+2y=x-3y与x分之1+2y=3有何本质不同
(2x+y-1)(2x-y+1)-(3x+y)(3x-y),其中x=5分之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分之2(X-Y)-4分之X+Y=-1,6(X+Y)-4(2X-Y)=16
{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)+...-(
方程2分之x+y+2分之x-y=7,4(x+y)-5(x-y)=2
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
解方程组{x=2y,x+y=3; {y=1-x,3x+2y=5 ;{3x+5y=5,3x-4y; {2分之x-3分之y+
解方程:3分之2(x-y)-4分之x+y=-1,3(x+y)-6(x-y)=6
(3x-y)^2+(3x+y)(3x-y),x=1,y=-2
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27