Question

In an AP, show that Am+n +Am-n =2Am​

Answer 1

Step-by-step explanation:

Am+n=A+(m+n-1)D

Am-n=A+(m-n-1)D

Am+n+Am-n=A+(m+n-1)D+A+(m-n-1)D

=2A+(m+n-1+m-n-1)D

=2A+(2m-2)D

=2[A+(m-1)D]

=2Am