1.(X-Y)/13=Y/7
1.(X-Y)/13=Y/7
已知(x-y)/13=y/7,则(x+y)/y=
1.x+x+x+y+y=6.4 y+y+y+x+x=7.1 x= ( ) y=( ) 2.1,4,7,10,13……这串
1.解下列方程(1)(x+y=-2(x+z=13(y+z=1(2)(x-y-z=-1(3x+5y+7z=11(4x-y+
若3x=7y,则y分之x= ,x:(x:y)=
若3x=7y,则y比x= ,x:(x+y)=
x-y=13 x=6y-7
高中数学题(有关线性规划):已知变量x、y满足约束条件【x-y+2=1.x+y-7
已知5x=7y,x与y( )
解方程组 1.x=2y+3 x-3y=20 2.x-y=13 x=6y-7
1.x+y+z=21,x-y=1,2x+z-y=13.2.3x+2y+z=13,x+y+2z=7 ,2z+3y-z=12
1.、已知线段x,y,如果(x+y):(x-y)=a:b,求x、y