math
posted by shakira.shakira on .
if x,y,z represents consecutive terms in an Arithmetic progression, prove that y is = (x+z)/2

State that the difference to be 'b'
y = x + b
b = y  x. ..(1)
z = y + b = x + 2b
b = (z  x)/2. ..(2)
Combining equations (1) and (2):
b = y  x = (z  x)/2
y = (z + x)/2