Hi,
I think this is the table, correct?
Number of Tubes 3 5 7
Cost ($) 12 20 28
we can calculate the prize as the number of tubes multiplied by 4:
3*4=12
5*4=20
7*4=28
which means that one tube costs 4 dollars!
However, in the store A two tubes cost 7, which means that one costs half of this -3.5
So Store B is more expensive (4 dollars per 4 rather than 3.5 as in Store A).
Let y be the temperature
Let m be the rate of temperature drop in degrees per hour
Let x be the number of hours elapsed since 8PM
The initial temperature (at x = 0) is 0
y = mx
Four hours from 8 PM, the temperature was -16.8 degrees
-16.8 = m(4)
m = -4.2 degrees per hour
At 9PM, one hour will have elapsed.
y = -4.2(1)
y = -4.2 degrees
Answer:
12
Step-by-step explanation:
Is it cheaper then without it? If so you should