Question

the sum of the series 1 by 2 +1by 3 +1by 6.....+to 9 term is​

Answer 1

Answer:

-3/2

Step-by-step explanation:

a = 1/2

d = a2 - a1 = a3 - a2

$\frac{1}{3} - \frac{1}{2} = \frac{1}{6} - \frac{1}{3} \\ \frac{2 - 3}{6} = \frac{1 - 2}{6} \\ \frac{ - 1}{6} = \frac{ - 1}{6} \\ d = - \frac{1}{6}$

S9 =

$= \frac{n}{2} (2a + (n - 1)d) \\ = \frac{9}{2} (2( \frac{1}{2} ) + (9 - 1) - \frac{1}{6} ) \\ = \frac{9}{2} (1 + 8( - \frac{1}{6} )) \\ = \frac{9}{2} (1 - \frac{8}{6} ) \\ = \frac{9}{2} ( \frac{6 - 8}{6} ) \\ = \frac{9}{2} \times - \frac{2}{6} \\ = - \frac{9}{6} \\ = - \frac{3}{2}$

hope you get your answer