Answers

2016-07-06T22:01:54+08:00
An=59; a1=3; d=4; n=?

an=a1+(n-1)d
59 = 3 + (n-1) 4
59 - 3 = 4n - 4
56 + 4 = 4n
60 = 4n
*divide both sides by 4*
15 = n

so there are 15 terms :)
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