I think its he didnt eliminate the same variables
Answer:
300L per hour
Step-by-step explanation:
The rate of change of volume of blood pumped by the teenager's heart expresses the volume of blood pumped with respect to hour.
Rate of change of volume of blood = 
= 
= 300L/hour
The rate of change of volume of blood by the teenager's heart is 300 litres per hour. This implies that his/ her heart pumps 300 litres of blood every hour.
♂️♂️ -15 a parallel, clarify your question
A) Because the 80 is by itself that would be the start up fee.
B) We are told x is the number of months. Since the X is being multiplied by 30, we know that would be the total monthly cost. This is being added to the 80, which does not have an exponent, so we know this is a single cost, which would be the start up fee.
C) Copying the same format as the given equation above, change the numbers:
f(x) = 20 + 35x
D) I used the same format as the first equation, which meant replacing the start up cost from the original one ( 80) with the start up of the new one (20). Then I changed the monthly cost from the original one (30) with the monthly cost of the new one (35).
E) Replace x in each equation with 8 and calculate the cost of each:
80 + 30(8) = 80 + 240 = $320
20 + 35(8) = 20 + 280 = $300
The second club (club B) is the cheaper option for her.