Answer:
37 boxes
Explanation:
At first, Dymin had some boxes. Let x be the starting number of boxes.
Then, she bought 7 more boxes. Let y be the new number of boxes that she had.
y = x + 7
Next, her little brother destroyed half of them. It means half of y. So, the number of boxes left is
Number of boxes = y/2
The number of the boxes left is 22 boxes. Then, we can use the equation above.
Number of boxes = 22
y/2 = 22
Substitute y = x + 7 into the equation.
(x + 7)/2 = 22
x + 7 = 44
x = 44 - 7
x = 37
Thus, Dymin has 37 boxes at first.