Question

find the sum of 9+16+25+36....100​

Answer 1

Answer:

763

Step-by-step explanation:

a = 9

d = 16-9 = 7

L = 100

L = a +(n-1)d

100 = 9 + (n-1)7

91 = (n-1)7

n-1 = 13

n= 14

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

= 14/2 ( 2(9) + (14-1) 7)

= 7 ( 18+ 91)

= 7(109)

763

Answer 2

Answer:

763

Step-by-step explanation:

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

= 14/2 ( 2(9) + (14-1) 7)

= 7 ( 18+ 91)

= 7(109)

763