First solve the equation.
Start by distributing the 5 through the parenthses on the left side.
On the left we get 5x - 10 and on the right we have 5x - 7.
So we have the equation 5x - 10 = 5x - 7.
Now subtract 5x from both sides to get -10 = -7.
Since -10 = -7 is a false statement, this equation has no solution.