x^2-4y^2=-15,2y-x=3则x+2y=?
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x^2-4y^2=-15,2y-x=3则x+2y=?
![x^2-4y^2=-15,2y-x=3则x+2y=?](/uploads/image/z/1493789-5-9.jpg?t=x%5E2-4y%5E2%3D-15%2C2y-x%3D3%E5%88%99x%2B2y%3D%3F)
x^2-4y^2=(x+2y)(x-2y)=(x+2y)*(-3)=-15所以x+2y=5
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
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
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
(x+y)(x+2y)(x+3y)(x+4y)=-40
已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
已知x*x+4x+y*y-2y+5=0,则x*x+y*y=?
【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2=
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1