There is a percentage of 8.333333333333333333333%
I’m so sorry I need points but I’m gonna manifest that someone smarter will see this and answer
You just add the lengths of RS and ST together. In your case RT= 24
P(x) =9x +30
the tips are a flat rate so it’s a constant 30 while the 9 per hour is dependent on the hours worked which is why it is attached to x as a coefficient