Answer:
Step-by-step explanation:
Proportionality constant is given by the formula,
y = kx
Where,
y is the dependent factor
x is the independent factor
A. A small pizza costs $9.00 and each additional topping costs $0.75
Let pizza be x, toppings be c and cost = y
y = x + c - linear form
B. A health club charges $45 per month.
Let charges be y, cost be c and months be x
y = c/x - inverse relationship
C. A bike rental store charges $20 as a flat fee, plus $5 per hour.
Let charges be y, flat fee be c, charge rate be t and hour be x
y = c + (t × x) - linear form
D. A car travels 60 miles in 1 hour, 120 miles in 2 hours, and 180 miles in 3 hours.
Let distance be y and hours of travel be x
y = 60 × x
E. A student earns $12 for each hour she tutors.
Let earnings be y and hours be x
y = 12 × x
Note: All proportional functions are linear, but not all linear functions are proportional.
From the above,
A, C, D, E Are all proportional.