Question

find the sum of first 09 terms in given A.P 0.9, 0.7, 0.5​

Answer 1

Answer:

S9=n/2(2a+(n-1)d)

a=0.9. d=0.-2

9/2(2*0.9+(9-1)*-0.2

9/2(1.8+(8*2/10)

9/2(1.8+8/5)

9/2*(18/10+8/5)

9/2(9/5+8/5)

9/2*13/5=

117/10

11.7. Answer