mike charges 100 dollars service charge plus 65 dollars per hour.
amy charges 40 dollars service charge plus 80 dollars per hour.
the cost to repair from mike is 100 + 65 * x.
the cost to repair from amy is 40 + 80 * x.
let x = 3 and you get:
the cost to repair from mike is 100 + 65 * 3 = 295 dollars.
the cost to repaid from amy is 40 + 80 * 3 = 280 dollars.
as long as the time to repair is 3 hours or less, the cost to repair will be cheaper from amy.
As a function this is x=3 y=3
Answer:
-37.5 m
Step-by-step explanation:
If we assume that "one full day" is 24 hours, then 15 hours represents the fraction 15/24 of a day. Since the drilling rate was constant, and was presumed to start from a height of 0, the height after 15 hours is that fraction of the day's work:
... (15/24)×(-60 m) = -37.5 m