500 divided by 60 = 8.33... (but you round it to 8)
it would take her about 8 minutes.
2001 gallons used in 5 days, so the average for one day is 2001/5=400.2 gallons.
Let the speed off the walk way be x and speed of the walkway be y
x+y=6....i
x-y=2....ii
adding the above equation we get:
2x=8
thus
x=4 ft/s
and
y=6-4=2 ft/s
thus the speed off the walk way is 4 ft/s
the speed of the moving walkway is 2 ft/s
First step
Using substitution you can fill 2x + 11 in for the y part of the first equation
This will look like: 2x + 11 = -x^2 -2x + 8
Second step
Now we need to solve for the variable by combining like terms you can start by adding x^2 + 2x -8 to both sides
You get 0 = x^2 +4x +3
Third step
Factor
(X+3)(x+1)=0
If you need the y values you can fill in x= -3 to the second equation y= 2(-3) + 11 and y=5
First point is (-3,5)
The other point is found by filling x=-1 into the second equation: y= 2(-1) +11 and y = 9
Second point is (-1,9)