The given equation is
5(x - 3) = x + 13
We want to test if x = 6 is a solution. We would substitute x = 6 into the equation. We have
5(6 - 3) = 6 + 13?
5(3) = 6 + 13?
15 = 19?
Since both sides of the equation is not equal, then
x = 6 is not a solution of the equation