Answer:
2 meters
Explanation:
The area of the original garden is 24 square meters. John wants to double that area to 48 square meters by increasing the length and width by the same amount.
x + 12 = 0 or x - 2 = 0
x = -12 or x = 2
We discard the negative solution, so x = 2.
So John must increase the length and width of his garden by 2 meters.