the annual household cost of telephone service in the US increased at a relatively constant rate of $27.80 per year from 1981 to 2001. IN 2001 the annual household cost of telephone service was $914.

Question

a:What was the annual household cost of telephone service in 1981?

B: Write an equation that gives the annual household cost of telephone service as a function of the number of year since 1981.
C: find the household cost of telephone service in 2000