Question

A rectangular room has an area of 400 square foot. The length is 7 feet less than twice the width. How do you find the dimensions of the room?

Answer 1

$400=w\times (2w-7)$. Length is 25 ft and width is 16 ft.

Explanation:

You can put an equation to solve the problem:

$A=w\times l$

where l is $2w-7$

Now you can solve the question.

$400=2w^2-7w$

w will be 16 feet.

I used trial and error method to find w. If you want, you can use quadratic formula to solve the question. If w is 16 ft,

$400=(2\times {16}^2)-(7\times 16)$

$400=512-112$

It satisfies the equation.

Length is 25 ft and width is 16 ft.