Income tax in a particular country is calculated according to the following rate schedule:

20% on the first $18,000 of income

38% on the next $36,000 of income

49% on any further income

a. How much income tax should be paid by someone making $31,300?

b. How much income tax should be paid by someone making $71,900?

c. Construct a piecewise function that gives the tax for $x of income.

this is correct

a) 0.2*18000 + 0.38*(31300-18000)

=3600+5054=

answer = 8654

b) x = $ 71900

y = 0.2*18000 + 36000*0.38 + ( 71900 -18000 -36000)*0.49

= $ 26051

need help in c .. please show work