3x-2y-7=0,则6y-9X一6=
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
若2x-3y+4=0则x(x*x-1)+x(5-x*x)-6y+7
y-3x=2,y-5x=4,y-7x=6,y-9x=8,y-11x=0方程组,
已知x,y为实数,根号3x+4 +y^2-6Y+9=0则x+y=?
x+y=3 x+2y=9 3/x+1=y y-x=3 y=2x-3 y-3x=1 2(x+1)-y=6 7x-5y=-9
已知x-2y=3,则(2x+y-6)/(3x-y-9)=?
解方程一;{x+y-z=6,x-3y+2z=1,3x+2y-z=-7.②{3x+4z=7,2x+3y+z=9,5x-9y
一:2x-3y=7 二:x/2 - y-2/6=x+y/3 + 1
【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2=
2 21.(2x+3y) -(x+2y) 2 2 2 22.3|x-3|+x -6xy+9y =0 则x y+2xy=?
已知x,y满足x²+y²-4x+6y+13=0则(3x+y)²-(3x+y)(3x-y)的
3x+2=y 5X+4=Y 7X+6=Y 9X+8=y 11x=y要如何计算