Find the solution set of x + 5 = 16.

• If x is replaced by 11, the equation is true. Since no other replacement for x makes the equation true, the solution set is {11}.

If x is an integer, what is the solution set of x + 2 = 2?

• Since 0 + 2 = 2 and no other value of x makes the equation true, the solution set of x + 2 = 2 is {0}.

Solve 2x - 18 = 4.

• You can simply try replacing x with different values until you find that 11 is the solution and there appears to be no other solutions.