Respuesta :
Answer:
59330 feet
Step-by-step explanation:
If length is equal to 21 feet, then x=21
Width will be f(21)=6*(21)^3+9*(21)^2-210+5=59330 feet
The width of the rectangle with the given perimeter and length is 29,686 inches.
Given that, the perimeter of a rectangle = 6x³+ 9x² - 10x + 5 and length=x.
We need to find the width of the rectangle when the length is 21 inches.
What is the perimeter of a rectangle?
The perimeter of a rectangle is the total distance of its outer boundary. It is twice the sum of its length and width and it is calculated with the help of the formula: Perimeter = 2(length + width).
Let the width of the rectangle be y.
Now, length=x=21 inches.
Thus, 6x³+ 9x² - 10x + 5 = 2(x+y)
⇒6×21³+ 9×21² - 10(21)+ 5=2(21+y)
⇒55,566+3,969-210+5=42+2y
⇒59,372=2y
⇒y=29,686 inches
Therefore, the width of the rectangle with the given perimeter and length is 29,686 inches.
To learn more about the perimeter of a rectangle visit:
https://brainly.com/question/2142493.
#SPJ2
