Answers

2016-04-06T13:57:52+05:30
x+y, x-y, x-3y
The above series is in arithmetic progression
a = x+y
d = -2y
n = 22
sₓ = n/2 [ 2a + (n-1)d ]
sₓ = 11 [ 2x+2y + 11(-2y) ]
sₓ = 11 [ 2x+2y-22y ]
sx = 22x-220y
0