Question

If x,y,z are in A.P p.t. y+z,z+x,x+y are in A.P

Answer 1

x,y,z are in a.p.
Then
y-x = z-y
or, x-y = y-z. ...............................(1)

y+z, z+x , x+y

(z+x)-(y+z) = (x+y) - (z+x)

or, x-y = y-z

Therefore, the give series is an a.p.