To solve this equation, you need to use the distributive property. You first multiply 3 and a and you get 3a. Then you multiply 3 and -1 and you get -3. You add -3 to 34 which is 31. Then you divide 31 by 3 and you get 10.3. Unfortunately. I have no idea how to explain why backtracking helps you solve the equation but I hope this helps you a little bit.
