A photograph is in the shape of a rectangle. It has a Iength of (x + 2) inches and a width of (x -2) inches. What is the area of the photograph?

Respuesta :

Answer:

The area of the photograph is:  [tex]A=x^2-4[/tex]      

Step-by-step explanation:

Given

The length of rectangular photograph = [tex]l[/tex] = (x + 2) inches

The width of rectangular photograph = [tex]w[/tex] = (x - 2) inches

To determine

The area of the photograph

Important Tip:

Given that the photograph is in the shape of a rectangle. Thus, we can use the formula involving the area of a rectangle to determine the area of a photograph.

The Area of the photograph can be determined using the formula

[tex]A = wl[/tex]

where

  • [tex]A[/tex] is the area
  • [tex]l[/tex] is the length
  • [tex]w[/tex] is the width

now substituting [tex]l = (x + 2)[/tex] and [tex]w = (x-2)[/tex] in the formula

[tex]A = wl[/tex]

[tex]A = (x-2) (x+2)[/tex]

Apply Difference of Two Squares Formula:  [tex]\left(a-b\right)\left(a+b\right)=a^2-b^2[/tex]

[tex]A=x^2-2^2[/tex]       ∵ [tex]a=x,\:b=2[/tex]

[tex]A=x^2-4[/tex]        ∵ [tex]2^2=4[/tex]

Therefore, the area of the photograph is:  [tex]A=x^2-4[/tex]