Question

Q.7

Answer 1

Let 'a' be the first term and 'd' be the common difference of fiven A.P.

`L.H.S=(m+n)^(th) "term" +(3-n)^(th)`

       ` =[a+(m+n-1)d]+[a+(m-n-1)d]`

         `=[a+md+nd-d]+[a+md-nd-d]`

         `=a+md+nd-d+a+md-nd-d`

         `=2a+2md-2d`

         `=2(a+md-d)`

         `=2[a+(m-1)d]`

         `=2xxm^(th) "term"`

         `=R.H.S`