600 feet of tape because 4 +4 for two sides of the window is 8 and 3+ 3 is 6, 14 plus the foot of overlap is 15 x 40 is 600.
The quadratic formula is -b plus minus the square root of b^2-4ac all over 2a.
Here, a=1, b=13, and c=30.
The only option that fills in the values correctly is D
