10. Given Sn = 8n2 – 5n, find a, d and an.
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n = 1,2,3
S1= 8(1)^2-5(1)
S1=8-5
S1=a1=3
S2= 8(2)^2-5(2)
=32-10
S2=22
a2=s2-s1
22-3
=19
Hence a=3
d= a2-a1
19-3
=16
Similar an=sn-s(n-1)
=put value and find an and value of s(n-1) is 8(n-1)^2-5(n-1)
S1= 8(1)^2-5(1)
S1=8-5
S1=a1=3
S2= 8(2)^2-5(2)
=32-10
S2=22
a2=s2-s1
22-3
=19
Hence a=3
d= a2-a1
19-3
=16
Similar an=sn-s(n-1)
=put value and find an and value of s(n-1) is 8(n-1)^2-5(n-1)
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