Answer:
z = -ln│5eᵗ + C│
Step-by-step explanation:
dz/dt + 5eᵗ⁺ᶻ = 0
dz/dt = -5eᵗ⁺ᶻ
dz/dt = -5eᵗeᶻ
-e⁻ᶻ dz = 5eᵗ dt
e⁻ᶻ = 5eᵗ + C
-z = ln│5eᵗ + C│
z = -ln│5eᵗ + C│
Given:
f(x) = 70n - 400 : equation for monthly profit.
n = number of students enrolled in the guitar class.
70 refers to the amount charged per student.
400 is the fixed expense made by the instructor.
For the instructor to have a profit, the product of 70n must be more than 400.
400/70 = 5.7 or 6
There must be at least 6 students enrolled in class for the instructor to generate profit.
f(x) = 70(6) - 400 = 420 - 400 = 20
1000 = 70n - 400
1000 + 400 = 70n
1400 = 70n
1400/70 = n
20 = n
There must be 20 students enrolled in class for the instructor to earn 1000 in profit.
1000 = 70(20) - 400
1000 = 1400 - 400
1000 = 1000
