Answers

2015-01-18T20:41:56+08:00
Let:
a1= 2
d=3   (5-2)
n= 14

S=n/2[2a1+(n-1)d]
S=14/2[2(2)+(14-1)3]
S=14/2[4+(13)3]
S=14/2[4+39]
S=7[43]
S=301
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