Surely you can determine T1 ??
Clearly d = -2b
So now just apply your formulas.
a) the value of t1 and d (2 marks)
b) an explicit formula for the general term (2 marks)
c) t20 (2 marks)
3a, 3a – 2b, 3a – 4b, 3a – 6b, …
1 answer