Question

A rectangular deck is 12 ft by 14 ft. When the length and width are increased by the same amount, the area becomes 288 sq. ft. By how much were the dimensions increased?

2 ft
4 ft
8 ft
10 ft

Answer 1

To solve this problem you must apply the proccedure shown below:

1. You have the following information given in the problem above:

- The rectangular deck has the following dimensions: 12 ft by 14 ft.
- When the length and width are increased by the same amount, the area becomes 288 ft².

2. Therefore, you have:

A=bxh

288=(12x)(14x)
288=168x²

3. When you clear the x, you obtain:

x=√288/168
x=(2√21)/7≈1.31

Answer 2

4 ft option (c)

Explanation:

Length of a rectangular deck = 12 ft.

width of rectangular deck= 14 ft.

let the length and width are increased by the x ft.

New length = (12 + x) ft

New width = (14+ x) ft.

area of rectangular width = length × width

according to the question

(12+x)(14+x) = 288

168+
`x^(2)`=+14x+12x = 288

`x^(2)`+26x = 228-168

`x^(2)`+26x-120=0

`x^(2)`+ 30x-4x-120=0

x(x+30)-4x(x+30)

x=4 or x=-30

x=-30 is rejected

Hence, the length and width are increased by the 4 ft.