Answers

2016-07-20T18:53:30+08:00
To get the nth term which is -18 we have to use this formula: 

an = a1 + (n-1)d

-18 = 7 + (n-1)-5

-18 = 7 -5n + 5

5n = 7 + 5 + 18

5n = 30

5n/5 = 30/5

n = 6

Therefore, -18 is a6
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