To begin you want to isolate the g. So you add to both sides. On the left is cancels out so it looks like this:
Next, you find the Least Common Denominator (LCD) which is 16. And since one fraction already has a denominator of 16 you leave it as it is. The other fraction, however, needs to be multiplied (both top and bottom) by 4 to get the denominator (bottom) to 16. So: