Question

I need some help please. Write a function rule to describe each statement...

Answer 1

You could see the pattern

it cost 3.8 cent to print 1 dollar,

It cost 2 x 3.8 cents to print 2 dollar

it cost 3 x 3.8 cents to print 3 dollar

First equation 
f(x) = 3.8 x

Same with second equation,
f(x) = 15x

for equation 3, it would be :

y = 1.50 x - 0.8x

Hope this helps