Question

rectangular stained glass window is 2 feet by 4 feet. A clear glass border is constructed around the stained glass window. The width of the border is equal and was made out of 7 square feet of clear glass. What is the width of the border?

Answer 1

S=2(4x+2x)+4x^2=4x^2+12x

4x^2+12x=7
4x^2+12x-7=0
D=12^2-4x4x(-7)=256
X1=(-12-16)/(2x4)=-3.5 impossible
X2=(-12+16)/(2x4)=0.5

A