Question

if S 5= 16 and S6= 21 ,find t8​

Answer 1

t8=31

step by step

As per given condition,

S 5=16 and S 6=21

a+(5-1)d=16 .....(for S5)

a+4d=16....(1)

a+(6-1)d=21....(for S6)

a+5d=21...(2)

After substraction of equation 1&2

we get;

d=5 & a=-4

t8=-4+(8-1)5

t8=-4+35

t8=31

Hope it helps.......

Answer 2

here is your answer...

follow..