3（x-2）+5=6x+2
3x-6+5=6x+2
6x-3x=-1-2
3x=-3
解为x=-1
3kx-1=k-x
3kx+x=k+1
解为x=(k+1)/(3k+1)
由题意-1-(k+1)/(3k+1)=2
去分母-3k-1-k-1=6k+2
6k+4k=-2-2
10k=-4
k=-2/5