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.
![(6 + x)(4 + x) = 48](https://img.qammunity.org/2023/formulas/mathematics/high-school/f0sfl22inhh9ptp8k8zjgtm9vsqxxm22tt.png)
![24 + 10x + {x}^(2) = 48](https://img.qammunity.org/2023/formulas/mathematics/high-school/nkkl1a0kwo5kxacai8gg2kqebvrfzvekqn.png)
![{x}^(2) + 10x - 24 = 0](https://img.qammunity.org/2023/formulas/mathematics/high-school/4dpk0hcnbuxmpsxtczq98txzm080xj37.png)
![(x + 12)(x - 2) = 0](https://img.qammunity.org/2023/formulas/mathematics/high-school/olgd77r4m6hc5hoesnlqlk8a1hgzzce9tv.png)
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.