Answer:
c(2) = -10
Step-by-step explanation:
The first equation says that the first term of the sequence is -20.
The second equation is saying that to find any term of the sequence, add 10 to the previous term.
c(2) = c(2-1) + 10
c(2) = c(1) + 10
c(2) = -20 + 10 = -10