9:2=36:y

9:2=36:y 二元一次方程：{3X=2Y,3X+4Y=36 {3X+4Y=10,4X+Y=9 {2X-Y=6,X+2Y=-2 {X+Y 已知4x=9y求(1)x+y/y (2)y-x/2x (y-2)(y的2次幂-6y-9)-y(y的2次幂-2y-15),其中y=-2 已知7/3*根号（9y）-y-2y*1/y=-2,求y的值 2y''+y'-y=0 1.5y+8y-6y=2y-3 3x-2y=9 x-3y=2 x+y=5 x+2y=3 y=x 2x+y=8 解方程组x:y=2:3和5x+3y=38 3y+x/y=8和9y-2x/y=9 3y=2x y/3=x/2 12/x=9/y y/x=?y/x=?x/y=? 已知2x-y/x+2y=3,求2(2x-y)/x+2y-9(x+2y)/2x-y+3的值. 已知4x2+9y-4x-6y+2=0 求根号y/根号x+根号y - 根号y/根号x-根号y