The distance traveled will be the value of d when h=0 so:
-d^2+10d+5=0 which is the same as:
d^2-10d-5=0 now complete the square to find d, add 5 to both sides
d^2-10d=5 halve the linear coefficient, square it, and add it to both sides
d^2-10d+25=30 now the left side is a perfect square...
(d-5)^2=30 take the square root of both sides
d-5=±√30 add 5 to both sides
d=5±√30 since d>0
d=5+√30 ft
d≈10.48 ft (to nearest hundredth of a foot)
