Answers

2016-06-22T22:04:37+08:00
An=a1+(n-1)d
Assume
an=3
a1=24
n=5
answers:
an=a1+(n-1)d
3=24+(5-1)d
3=24=(4)d
3-24=4d
-21=d
let's find the a1
an=a1+(n-1)d
3=a1+(5-1)-21
3=a1+(4)-21
3=a1+(-81)
3+81=a1
84=a1
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