First multiply the 2 into the parenthesis. Then add the 10 and 2 in order to simplify. Then subtract 4a from both sides. This gives you 12=3a-3. Add 3 on both sides, this gives you 15=3a. Divide 3 on both sides which will give you a =5
The reason for that is if u were to make 4/6 and 2/10 have the same denominator which would be 40/60 and 12/60 40 is greater than 12 and that fraction is equivalent to 4/6
