Solve the inequality for v:
20 > v - 4
When the variable is at the right of the inequality, it's a good idea to flip the inequality, that is, swap the sides and (very important), swap the symbol:
v - 4 < 20
Now we add 4 to both sides:
v - 4 + 4 < 20 + 4
Operating:
v < 24
This is the answer