Answer
The solution set is {2/3,-8}.
Work Step by Step
You need to create two seperate equations.
5x+1=4x-7
5x+1-1=4x-7-1
5x=4x-8
5x-4x=4x-4x-8
1x=-8
1x/1=-8/1
x=-8
and
5x+1=-4x+7
5x+1-1=-4x+7-1
5x=-4x+6
5x+4x=-4x+4x+6
9x=6
9x/9=6/9
x=2/3
The solution set is {2/3,-8}.