Answer: a = 22
Step-by-step explanation: First isolate a/3 by adding 7 to both sides of the equation. That gives you a/3 = 22.
From here since a is being divided by 3, multiply both sides of the equation by 3 so a = 66. We can check our answer by substituting a 66 back in for a in the original equation and we have
or 22 - 7 = 15 or 15 = 15. Since this is a true statement, our answer checks.