The area of a rectangular wall of a barn is 175 square ft.it’s length is 6feet longer than twice its width.find the length and width of the wall barn.

Respuesta :

Answer:

[tex]L =21.945[/tex] --- Length

[tex]W = 7.9725[/tex] --- Width

Step-by-step explanation:

Given

Let

[tex]L \to Length[/tex]

[tex]W \to Width[/tex]

So:

[tex]Area = 175[/tex]

[tex]L = 6 + 2W[/tex]

Required

The dimension of the rectangle

The area is calculated as:

[tex]Area =L*W[/tex]

This gives:

[tex]175 =L*W[/tex]

Substitute: [tex]L = 6 + 2W[/tex]

[tex]175 =(6 + 2W)*W[/tex]

Open bracket

[tex]175 =6W + 2W^2[/tex]

Rewrite as:

[tex]2W^2+ 6W -175 = 0[/tex]

Using quadratic formula:

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

This gives:

[tex]W = \frac{-6 \± \sqrt{6^2 - 4*2*-175}}{2*2}[/tex]

[tex]W = \frac{-6 \± \sqrt{1436}}{2*2}[/tex]

[tex]W = \frac{-6 \± 37.89}{4}[/tex]

Split

[tex]W = \frac{-6+ 37.89}{4}, W = \frac{-6- 37.89}{4}[/tex]

[tex]W = \frac{31.89}{4}, W = \frac{-43.89}{4}[/tex]

The width cannot be negative;

So:

[tex]W = \frac{31.89}{4}[/tex]

[tex]W = 7.9725[/tex]

Recall that:

[tex]L = 6 + 2W[/tex]

[tex]L =6 + 2 * 7.9725[/tex]

[tex]L =21.945[/tex]