contestada

A sequence consists of the positive odd integers 1, 3, 5,. What's the sum of the first 12 terms of the
sequence?

Respuesta :

hi

we have an aroithmetic serie of first term 1 and  pace  2

so sum of 12 first terms, namming  1 as  S1 and  12th term as  S12

S12 =  1 + 2*11 = 23

formula of summ :      number of term *  (  final term + first term) / 2

So sum of terms  from S1 +S12 =    12   ( S12 +S1 )  / 2  =  12 * ( 23+1) /2

12*  12=  144

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