The answers on the right are in reverse order to the questions on the left.
I find it easier to see if I have a picture.
12+4=16 the second hour. (The first of the next three hours)
16+4=20 the third hour (the second of the next three)
20+4=24 the fourth hour( the last of the next three hours)
To solve for y you need to first multiply both sides by 4. This will give you: 4y - 4A / 3 = A + 3B
Next you need to multiply both sides by 3: 4y - 4A = 3A + 9B
Now you need to add 4A to both sides: 4y = 7A + 9B
Now divide both sides by 4:
Y = 7A/4 + 9B/4
The answer for this question is 0.2
