Using the factor label method, you would set up your ratio like so:
Using the side of the square find the area:
Area = 30^2 = 900 square feet.
The rectangles area is the same, 900 square feet.
Let the width = X
The length would be 2X + 70
Area = length x width
X * 2x+ 70 = 900
This expands to 2x^2 * 70x = 900
Use the quadratic formula to solve for x:
-70 +/- sqrt(70^2-4*2(-900))/2*2
X = 10
Width = x = 10 feet
Length = 2x + 70 = 90 feet
Represent the unknowns.
<span>Let x = length </span>
<span>since the width is 3/4 of the length, </span>
<span>Let (3/4)x = width </span>
<span>Recall that the area of rectangle is just width multiplied by the length, </span>
<span>A = w * l </span>
<span>Substituting, </span>
<span>432 = (3/4)x * x </span>
<span>432 = (3/4)x^2 </span>
<span>432 * 4/3 = x^2 </span>
<span>576 = x^2 </span>
<span>Get the square root of both sides, </span>
<span>x = 24 feet (length) </span>
