The length of a rectangular floor is 7 feet longer than its width w. The area of the floor is 505 ft2
.
(a) Write a quadratic equation in terms of w that represents the situation.
(b) What are the dimensions of the floor? Round to the nearest tenth.
Show your work.

Respuesta :

Answer:

Width is 19.24 ft and length is 24.24 ft

Step-by-step explanation:

Step 1:  Write an equation

[tex]A = l * w[/tex]

[tex]505\ ft^2 = (7+w) * w[/tex]

[tex]505\ ft^2 = (w*w) + (w*7)[/tex]

[tex]505\ ft^2 - 505\ ft^2 = w^2 + 7w - 505\ ft^2[/tex]

[tex]0= w^2 + 7w - 505\ ft^2[/tex]

Step 2:  Determine the dimensions

Use Quadratic formula

[tex]x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}[/tex]

[tex]x=\frac{-7\pm\sqrt{(7)^2-4(1)(-505)}}{2(1)}[/tex]

[tex]x=\frac{-7\pm\sqrt{2069}}{2}[/tex]

[tex]x = \frac{-7\pm45.486}{2}[/tex]

[tex]x=19.24,\ -26.24[/tex]

Since length cannot be negative, we will use 19.24 for x.

Step 3:  Determine the length

[tex]l = w + 5[/tex]

[tex]l = 19.24 + 5[/tex]

[tex]l = 24.24[/tex]

Answer:  Width is 19.24 ft and length is 24.24 ft