Question 902541
The equation for the perimeter of a rectangle is P = 2L + 2W.
Equation 1: {{{48 = 2L + 2W}}}
Equation 2: {{{L = 2W}}}
Plug 2W into equation 1 for L.
{{{48 = 2*(2W) + 2W}}}
Multiply the 2 through.
{{{48 = 4W + 2W}}}
Combine like terms.
{{{48 = 6W}}}
Divide both sides by 6.
{{{highlight(8 = W)}}}
Now plug 8 into equation 2 for W and solve for L.
Equation 2: {{{L = 2W}}}
{{{L = 2*(8)}}}
{{{highlight_green(L = 16)}}}
---------------------------
Now it is time to calculate the cost of the fence.
The longer side costs $1.25/ft.
Multiply $1.25/ft by the Length of 16ft. Multiply that by 2 because there are two sides of the rectangle.
$1.25 * 16 * 2 = $40 for the long sides.
---------------------------
The short side costs $3.25/ft.
Multiply $3.25/ft by the Length of 8ft. Multiply that by 2 because there are two sides of the rectangle.
$3.25 * 8 * 2 = $52 for the long sides.
---------------------------
Now add the costs together.
$40 + $52 = $92
It will cost $92 to build the pen.