4x-2y=5.6;7x+4y=-5.6
已知实数x.y满足根号(x+y-8)+根号(8-x-y)=根号(3x-y-4)+根号(x-2y+7),求x,y
{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
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6
已知4x=9y求(1)x+y/y (2)y-x/2x
(x+y)(x+2y)(x+3y)(x+4y)=-40
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?
2x-y=2,求[(x²+y²)-(x-y)²+2y(x-y)]÷4y
已知2x-y=10,求[(x²+y²)-(x-y)²+2y(x-y)]/4y
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²