Question

if Tn= 6n + 5, find Sn

Answer 1

Tn = 6n+5
n=1
a=6+5=11
sn=n/2{2a+(n-1)d}
=n/2{a+[a+(n-1)d]}
=n/2{a+Tn} {Tn=a+(n-1)d}
=n/2{11+6n+5}
=n/2{16+6n}
=n{8+3n}
sn=n{8+3n}

Answer 2

HOPE THIS HELPS YOU.