Select the correct answer.

Joe wants to enlarge the rectangular pumpkin patch located on his farm. The pumpkin patch is currently 40 meters wide and 60 meters long. The new pumpkin patch will be [tex]$3x$[/tex] meters wider and [tex]$5x$[/tex] meters longer than the original pumpkin patch.

Which of the following functions will give the area of the new pumpkin patch in square meters?

A. [tex]$f(x)=15x^2+380x+2,400$[/tex]

B. [tex]$f(x)=15x^2+420x+2,400$[/tex]

C. [tex]$f(x)=15x^2$[/tex]

D. [tex]$f(x)=15x^2+2,400$[/tex]



Answer :

Let's solve this problem step-by-step.

The original dimensions of the pumpkin patch are:
- Width = 40 meters
- Length = 60 meters

Joe's plans to expand each dimension are:
- Width increase = [tex]\(3x\)[/tex] meters
- Length increase = [tex]\(5x\)[/tex] meters

So, the new width and length of the pumpkin patch can be represented as:
- New width = [tex]\(40 + 3x\)[/tex] meters
- New length = [tex]\(60 + 5x\)[/tex] meters

We need to find the area of the new pumpkin patch as a function of [tex]\(x\)[/tex].

The area [tex]\(A(x)\)[/tex] of a rectangle is given by the product of its width and length:
[tex]\[A(x) = \text{New width} \times \text{New length}\][/tex]
[tex]\[A(x) = (40 + 3x) \times (60 + 5x)\][/tex]

To expand this product, we will use the distributive property of multiplication over addition:

[tex]\[ A(x) = (40 + 3x)(60 + 5x) \][/tex]

Expanding this product:

[tex]\[ = 40 \cdot 60 + 40 \cdot 5x + 3x \cdot 60 + 3x \cdot 5x \][/tex]

[tex]\[ = 2400 + 200x + 180x + 15x^2 \][/tex]

Combine like terms (the terms involving [tex]\(x\)[/tex]):

[tex]\[ A(x) = 2400 + 380x + 15x^2 \][/tex]

Therefore, the function [tex]\(A(x)\)[/tex] that represents the area of the new pumpkin patch in square meters is:

[tex]\[ A(x) = 15x^2 + 380x + 2400 \][/tex]

Now, let's match this result with the given options.

A. [tex]\(f(x)=15 x^2+380 x+2,400\)[/tex]
B. [tex]\(f(x)=15 x^2+420 x+2,400\)[/tex]
C. [tex]\(f(x)=15 x^2\)[/tex]
D. [tex]\(f(x)=15 x^2+2,400\)[/tex]

Clearly, option A is the correct match:

[tex]\[ f(x) = 15x^2 + 380x + 2400 \][/tex]

Thus, the correct answer is:

A. [tex]\(f(x)=15 x^2+380 x+2,400\)[/tex]