Question

The area of a rectangular wall of a barn is 168 square feet. Its length is 10 feet longer than twice its width. Find the length and width of the wall of the barn.

Answer 1

So area is 168 sq ft

That means that length * width = 168 sq ft
Since length  = 10 + 2 w

we get (10+2w)(w)  = 168

Multiply it out and you get 2w^2 + 10w - 168 = 0

This is a quadratic equation. You can use the formula here, but i'll just tell you the answer

w = -12,  or 7
since it can't equal -12 (ever heard of a barn with a length of -12?), you figure out the answer is 7.

If the width is 7, then the length is 10+2(7) = 24.

Have a nice day!