Answer:
Constant of proportionality is 12
The cost of buying new bicycle changes 12 dollar per week
Step-by-step explanation:
we are given
The equation as

where
d represents the amount in dollars
w is number of weeks
now, we can compare it with

where
k is constant of proportionality
we can compare
and we get
k=12
So,
Constant of proportionality is 12
we can see that

So,
The cost of buying new bicycle changes 12 dollar per week
D and B are both the answers
Step-by-step explanation:
if the car speeds at a constant rate of 32mi/m
the number of miles travelled in the next 25 min
= 32 mi/m ×25m
800 miles in the next 25 min