18. a rectangle on a digital display board is made
so that its width varies directly as its length. the
current rectangle displayed is shown below. what
is the area of a rectangle that is 15 inches long?
(12.5 in.
5 in.

Step-by-step explanation:

The missing figure is attached.

Direct variation equations have the following form:

Where "k" is the Constant of variation.

Since  the width  of the rectangle varies directly as its length, you can write this equation:

Where "l" is the lenght in inches and "w" is the width in inches of the rectangle.

Observe in the figure that when ; then you can substitute them into the equation and solve for "k":

Therefore, the width is:

Since the area of the rectangle can be calculated multiplying its lenght by its width, you get that the area of the rectangle that is 15 inches long is:

i got 142 as my answer

step-by-step explanation: