Thread: Need help with algebraic word problem

Rain-Gutter Design:

An open rectangular gutter is made by turning up the sides of a piece of metal 20 in. wide. The area of the cross-section of the gutter is 50 in^2. Find the depth of the gutter.

So far this is what I have done:
A= LW
50 = L (20)
L = A/W = 50/20 = 2.5 in

Is this correct?

posted by mcruz

you have the right idea but are making a simple mistake.Express an equation in W and L equal to 20. You will then have two equations iin W and L.Solve and find W and LThen check so that givens are satisfied

bjh

Hello, mcruz65!

An open rectangular gutter is made by turning up the sides of a piece of metal 20 in. wide.
The area of the cross-section of the gutter is 50 in².
Find the depth of the gutter.

Code:

      *         *
      |         |
    D |         | D
      |         |
      * - - - - *
           W

The depth of the gutter is
The width of the gutter is


We have: . .[1]


The area is 50 in²: . .[2]


Substitute [1] into [2]: .

. . which simplifies to: .

Factor: .

Therefore: .


The depth of the gutter is 5 inches.

I really appreciate the help.

yes but ya also need to find the depth