Help me complete the proof!

Distributive Property means you can multiply the outside and inside of parenthesis.

Addition Property... means you can add the same value to both sides of the equation without changing it.  In this case you add 3x.

Subtraction Property... same as addition property, but with subtraction.  In this case subtract 10 from both sides.

Division property...  same as addition and subtraction properties but with division.  In this case divide both sides by 8.  

Technically the addition property can be used for the subtract 10 because you just add -10 and multiplication property could be used for the division, because you just multiply both sides by 1/8, but for the purpose of this equation, you would say subtraction and division.