<h3><u>Part A: An equation to represent this situation, where x represents the original length of the rectangle is:</u></h3>

<h3><u>Part B: Original length of the rectangle is 12 inches</u></h3>
<em><u>Solution:</u></em>
Given that,
A rectangle has a width of 2.5
Therefore,
width = 2.5 inches
Let "x" be the original length of the rectangle
When the length of this rectangle is decreased by 5 inches
Therefore,
New length = x - 5
The new area of the rectangle is 17.5 square inches
Therefore,
<em><u>The area of rectangle is given as:</u></em>


Thus original length of the rectangle is 12 inches