Question

The sum of arithmetic series 4+12+20+_ _ _ _ 100

Answer 1

Step-by-step explanation:

100+4 ^2 = 200^2 = 40000

2.

Answer 2

4+12+20+...........+100

4(1+3+5+7..........+25)

We know that ;

sum of first n odd numbers is n^2

4 (13^2)= 676