Sn equal to 3n square + 4n find a 25
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Heya !!
Sn = 3N² + 4N ---------------(1)
Now,
25th term = ( Sum of first 25 terms ) - ( Sum of first 24 terms )
Putting N = 25 in equation (2) , we get :
S25 = 3 × (25)² + 4 × 25
=> 3 × 625 + 100
=> 1875 + 100
=> 1975
Putting N = 24 in equation (1) , we get ;
S24 = 3 × (24)² + 4 × 24
=> 3 × 576 + 96
=> 1728 + 96
=> 1824
Therefore,
T25 = ( S25 - S24 )
=> ( 1975 - 1824 )
=> 151
Hence,
The 25th term is 151.
Sn = 3N² + 4N ---------------(1)
Now,
25th term = ( Sum of first 25 terms ) - ( Sum of first 24 terms )
Putting N = 25 in equation (2) , we get :
S25 = 3 × (25)² + 4 × 25
=> 3 × 625 + 100
=> 1875 + 100
=> 1975
Putting N = 24 in equation (1) , we get ;
S24 = 3 × (24)² + 4 × 24
=> 3 × 576 + 96
=> 1728 + 96
=> 1824
Therefore,
T25 = ( S25 - S24 )
=> ( 1975 - 1824 )
=> 151
Hence,
The 25th term is 151.
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