-625
use long multiplication to evaluate .
Interesting problem.
First - let's figure cost of each uniform at purchase.
3,000/40 = $75 each
When some uniforms were returned at $40 - there was a difference of $35 in what they paid and what they rec'd in return. ($75 - 35 = $40)
there are 60 minutes per hour
24/60 = 0.4 miles per minute
0.4*5 = 2
they will ride 2 miles in 5 minutes
Since it is parallel, gradient must be the same so it will be 1/2
y=1/2x+c
-7=1/2(0)+c
c=-7
equation is y=1/2x-7
