Question 954524
Area of window=2ft*4ft=8 sq ft
Area of window + border=8 sq ft+7 sq ft=15 sq ft
x=width added to width and length 
border width=(1/2)x
{{{(2ft+x)(4ft+x)=15ft^2}}}
{{{8+6x+x^2=15ft^2}}}
{{{x^2+6x-7=0}}}*[invoke quadratic "x", 1, 6, -7 ]
ANSWER:Border=(1/2)x=(1/2)1ft=6 inches.   .The width of the border is 6 inches.