Answers

2016-07-03T22:44:06+08:00
A1=-16 a7=12 d=?

an-ak/n-k=d

12-(-16)/7-1

28/6

4.7=d

a1=-16 a2= -11.3 a3=-6.6 a4=-1.9 a5=2.8 a6=7.5 a7=12.2

round off
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