Answer:
1a. 3y = 18
1b. y + 7 = 18
1c. 2y + 4 = 18
Explanation:
In each case, let's take the red boxes to be constant why the the green boxes represents the variable, y.
Thus,
1a. There are only 3 green boxes which gives us 18, therefore, the equation that expresses this would be:
3y = 18
1b. We have 7 red boxes which represents the constant, 7.
We also have 1 green box which represents the variable, y. Therefore, the equation that expresses this would be:
y + 7 = 18
1c. We have 4 red boxes = 4
We have 2 green boxes = 2y
Therefore, we would have:
2y + 4 = 18