<h2> <u>Rectangular</u> <u>Areas</u> <u>and</u> <u>Perimeters</u></h2>
The perimeter of a rectangle is given by:
In the problem we have these data:
- Length = a
- Width = -2x + 20
- Perimeter = 6 + 2 (-2x + 20)
We replace the data in the equation of the perimeter:
<h3>6 + 2 (-2x + 20) = 2 (a - 2x + 20) </h3>
We apply distributive property:
6 - 4x + 40 = 2a - 4x + 40
6 = 2a
6 ÷ 2 = a
3 = a
⇒ Length = 3
The area of the rectangle is given by:
We have these data:
- Length = 3
- Width = -2x + 20
We replace the data in the equation of the area:
<h3>Area = (3) (- 2x + 20) </h3>
We apply the distributive property and obtain:
Area = -6x + 60
<u>The expression representing the area of the rectangle will be -6x + 60</u>
<h3>I hope I've helped!</h3>