(1)1200+4y=500x (2)2400+20x=20y 求x,
已知方程组4x+2y=1,20x+8y,求x,y
已知4x=9y求(1)x+y/y (2)y-x/2x
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x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y
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
已知x²+y²+5=2x+4y,求代数式(2x²-(x+y)(x-y))x((x+y-1)
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
3X+2=X+20求X Y未知数
求y=(5x-1)/(4x+2) (x
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?