Question

the initial cost of an office fax machine is $100. after 1 year it's value becomes $80. what is the linear description model

Answer 1

answer could be vary, heres my design

f(t)=-20t + 100
where t is after t years, if its after one year just plug in 1 f(1)= -20*1 +100
if it is after 2 years you plug 2 for f(2)=-20*2 + 100