college algebra(piecewise functions)

Question

For the first 40 hours Kayla works per week, she gets paid $12/hr. For each hour over 40 worked, she gets paid $18/hr. Write a piecewise function to represent her total pay with respect to the number of hours worked. How much will she make for working 50 hours?

Answer 1

if x>40,

(x-40)*18 + 12*40 =

18x - 720+480 =

18x - 240

otherwise

12x

so for 50 hours,

40*12 + (50-40)*18 =

480 + 10*18 =

480+180 =

660

and

P(50) = 18(50)-240 = 900-240 = 660