The cost of the the phone and phone plan after 2, 12 and 24months is $290, $690 and $1170 respectively.
A linear equation is in the form:
y = mx + b
Where y,x are variables, m is the rate of change and b is the initial value of y.
Given the equation:
C = 40n + 210
Where C is the cost of a phone plan for n number of months.
After 2 months; C = 40(2) + 210 = 290
After 12 months; C = 40(12) + 210 = 690
After 24 months; C = 40(24) + 210 = 1170
The cost of the the phone and phone plan after 2, 12 and 24months is $290, $690 and $1170 respectively.
Find out more on linear equation at: https://brainly.com/question/14323743
