how to solve this problem in the picture above

Answer:
g=4
Step-by-step explanation:
If you're solving for g, you need to get it alone on one side. The way I did so was to subtract 7 from each side.
15 = 2g + 7
-7 -7
If you do that, the 7 on the right cancels out and you're left with 8 = 2g. To get the g alone, you divide it by it's base on both sides which in this case is 2.
8/2 = 2g/2
That will cancel the 2 out and will leave you with g on the right side and on the left side would be 4 because simple division (8/2=4)
Your final answer should be g = 4