An equation with no solutions, is whne no matter what the unknown is, it never will be true.
First, we can have the same unknown on both sides: 3x
And then we can solve the left hand side of the equation, adding all the numbers:
[tex]\begin{gathered} \text{Left-hand side:} \\ 7-5+3x-1=3x+1 \end{gathered}[/tex]Now, if we have the same 3x in the right:
[tex]3x+1=3x+\text{\_\_}_{}[/tex]We have to add in the right side of the equation a number different from 1. Let's take 2. Then we have:
[tex]3x+1=3x+2[/tex]And we can verify that this equation does not have any solutions, by substracting 3x on both sides, and we get:
[tex]\begin{gathered} 3x-3x+1=3x-3x+2 \\ 1\ne2 \end{gathered}[/tex]Which is never true, and thus the euqation does not have any solutions.