Answer:
$20
Step-by-step explanation:
15/3=5 which means that for every guest attending Carla's retirement party it must cost her $5 each.
Therefore if 4 guests come to the party it must mean 4(5) which is 20.
Hence $20
Answer:
A
Step-by-step explanation:
work out price of each for one bottle
A) $12.60 ÷ 7 = $1.80
B) $10.98 ÷ 6 = $1.83
C) $18.10 ÷ 10 = $1.81
D) $16.38 ÷ 9 = $2.82
we can clearly see that A is the cheapest
Answer:
The differential equation is 
Step-by-step explanation:
Differential equation for the rate of change in radiation level:
Radiation level is R.
Rate of change indicates that the radiation level R varies in function of time t, which mathematically means that we have:

After the reactor is shut down, the radiation from the nitrogen-17 decreases in such a way that the rate of change in the radiation level is directly proportional to the radiation level.
Rate of change is k. Decreases means that k is negative. Proportional to the radiation level of R means that -k multiplies R. So the differential equation is:

Answer:
1. x = 36 equation is x + 2x + 9 = 117, then solve for x
2. x = 50 equation is x + x + 12 = 112, then solve for x
Step-by-step explanation:
Answer:
n =3
Step-by-step explanation:
20 minutes to 1 hour can also be written as 20 minutes to 60 minutes.
when simplified, you get 1:3