Explanation:
y = 3x + 10 the fixed charge is 10$ so our constant should be 10, there is a 3$ fee every day so x represents the days so we can multiply the amount of days with 3 to find the total amount paid in fees.
For example, if we hired a ladder for 3 days then
y = 3x + 10
= 3 x 3 +10
= 9 + 10
= 19$
So, we spent 19$ dollars in total cost