Show that the sum of (m + n)th and (m – n)th terms of an A.P. is equal to twice the mth term

• take tn=a+(n-1)d
  then in l.h.s
  a+((m+n)-1)d + a+((m-n)-1)d=2(a+(m-1)d)......(1)
  then in rhs by condition
  2(a+(m-1)d)......(2)
  both are equal
  
  
• 12 years agoHelpfull: Yes(5) No(0)