5Q - 7 = 2/3
You could begin by adding 7 to each side :
5Q = 7 and 2/3
The rest of it will be a lot easier if you change the right side
to a single fraction. Do you remember how to do that ?
7 is the same as 21/3 . So 7 and 2/3 is the same as 23/3 .
5Q = 23/3
Divide each side by 5 :
Q = 23 / (3 x 5) = 23/15 = 1 and 8/15 .