What's the answer and how do you do this?

the rate for the first 3 minutes is a, since it's a flat-fixed value, thus the cost will be a.

for Jackson, t > 3, namely 4 and higher, if he's on the phone longer than 3 minutes say hmmm 4 minutes, the the last minute is at a rate r, and his cost will be 3a + r1. now let's check a table.

4 minutea + r13a + r(4 - 3)

5 minutesa + r23a + r(5 - 3)

6 minutesa + r33a + r(6 - 3)

t minutesa + r(t-3).

a28=58

step-by-step explanation:

a1=a1+(n-1)d

a28= 4+ (28-1)2

a28=4+(27)(2)

a28=4+54

a28=58