Question 77803
To determine if 5 is an a solution, just substitute your value in for x.

{{{3x-7=2x+1}}}
Now, let's plugin 5 for x and solve.
{{{3(5)-7=2(5)+1}}}
{{{15-7=10+1}}}
{{{8 NotEqual 11}}}

Therefore 5 is not a solution.