看不懂3/x=(y-6)/y是怎么等于y=6x/x-3的,麻烦你
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
简单的线性规划题,设Z=2y-x,满足X,y:y小于等于x,x+y大于等于2,y大于等于3x-6
4x-3y-6z=0,x+2y-7z=0是一个方程组,那么x-y+z/x+y+z的值等于
【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2=
若x的二次方减y的二次方等于6,x+y+3,x-y=?
已知x.x+y.y-6x-8y+25=0,求3x.x+5y的值
若/x+y-2/+(2x-3y+6)的平方等于0则x=( )y=( )
已知x,y满足x²+y²-4x+6y+13=0则(3x+y)²-(3x+y)(3x-y)的
当2x-y/x+y=3时,求代数式2x-y/2x+2y+x+y/6x-3y的值.
当2x-y\x+y=3时,求代数式2x-y/2x+2y+x+y/6x-3y的値.
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