In an AP,the sum of first n term is 3n2/2+13n/2

find its 25th term

n =1

S1 = 3/2+13/2 = 16/2 =8

S2 = 12/2 + 26/2 = 6+13 = 19

S2 -S1= 19-8 = 11=a2

a2-a1 =d

d= 11 -8 = 3

a25 = a+(25-1)d

= 8 + (24 x3)

= 72+8 =80

In an AP,the sum of first n term is 3n2/2+13n/2

find its 25th term

n =1

S1 = 3/2+13/2 = 16/2 =8

S2 = 12/2 + 26/2 = 6+13 = 19

S2 -S1= 19-8 = 11=a2

a2-a1 =d

d= 11 -8 = 3

a25 = a+(25-1)d

= 8 + (24 x3)

= 72+8 =80

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