Question 613635
We know that to find the area of a rectangle, you use this formula: {{{l*w=a}}}. Let's convert the words into something mathematical.

<p>A rectangle has a length that is 5 feet more than it's width (w+5). The area of this rectangle is 84 square feet (=84). 

<p>Let's plug in what we know into the area formula. {{{(w+5)*w=84}}}. 
Simplify: {{{w^2+5w=84}}} to {{{w^2+5w-84=0}}}. Let's use the quadratic formula to simplify. 

<p>*[invoke solve_quadratic_equation 1, 5, -84]

<p>The area can't be negative, so we're assuming {{{w=7}}}. That means that the width of the rectangle is 7, and the length {{{7+5=12}}}. The length is 12.