Answer:
a. s1 = -6; d = 4
Step-by-step explanation:
The difference between terms 3 apart will be 3 times the common difference:
d = (s8 -s5)/3 = (22 -10)/3 = 12/3 = 4
The difference between s1 and s5 will be 4 times the common difference, so ...
s1 = s5 -4d = 10 -4(4) = -6
These values match choice A: s1 = -6, d = 4.
