Question

for a G.P., if a = 1, r = -3/2 then S5 =? ​

Answer 1

Answer:

if r is less than 1 then

sn=a×(1-rn)÷(1-r)

=1×(1-(-3/2)5)÷(1-(-3/2))

1×(1+(3/2)5)÷(1+3/2)

1+243/32)÷5/2

(32+243)/32. ÷5/2

273/32÷5/2

273/32×2/5

273/80