What is the sum of the series?

The sum of given series is 44

Solution:

Given that we have to find the sum of the series

Given series is:

Substitute k = 1 to k = 4 to find the sum of the series

When k = 1:

When k = 2:

When k = 3:

When k = 4:

Therefore, the sum of series is given as:

Thus the sum of series is 44

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional