If we have that the equation is:

We need to proceed as follows to find the value of x (there are many ways to solve it. One is as follows):
1. Apply the distributive property at the left side of the equation:

2. Subtract 20 from both sides of the equation:

3. Divide both sides by -2:

If we substitute this value into the original equation, we have:

Therefore, we have that x = 3 is a solution of the equation:

After solving the equation, and then by checking the correctness of the value, we have that x = 3.
In summary, x = 3 is a solution.