The archway to the entrance of an art gallery can be

modeled by y = - } (x - 5) (x + 5), where x and y

are measured in feet. The x-axis represents the floor.

Find the width of the arch at floor level.

10 units

Step-by-step explanation:

if we're trying to find the width of the arch, then essentially we're trying to find where the arch ends so we can calculate that width right.

you can do this by find the zero's

0 = - (x-5) (x+5)

x = - 5,5

simply find the difference between these two values to get width = 10