3x/4+2y/4=2x/-1/3 2x/2+y/2=5x/4-4/4
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
若2x-3y+4=0则x(x*x-1)+x(5-x*x)-6y+7
数学题……555{(3x+y)(3x-y)-(x-5y)(5x-y)-(x-2y)²÷(-4x),x=-2.y
(x+2)(x+3) (x-4)(x+1) (y+4)(y-2) (y-5)(y-3)
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
(x+y)(x+2y)(x+3y)(x+4y)=-40
9y=3x-(x-1),4(x+y)-(2x+4)=8y