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
2(4)+6
8+6
=14
you’re welcome :)
It's 2.5 bc it goes up by 2.5 everytime
(f o g)(x)
g(x) = x + 2
Since it’s telling you to use g(x), you use (x + 2) as your new x value for function f.
f(x + 2) = 5(x + 2) + 5
= 5x + 10 + 5
= 5x + 15