Question

IN an A p t1=7.t2 00=393 fird 320r

Answer 1

Let, common difference=d

rth term =tr

1st term= a

Now mth term= tm=a+(m−1)d

Since, tm=n1

Therefore,

n1=a+(m−1) …… (1)

Now nth term tn=a+(m−1)d

Given ,tn=m1

Therefore,

m1=a+(n−1) …… (2)

Subtract equation (2) from equation(1)

n1−m1=(m−1)d−(n−1)d

mnm−n=(m−n)

d=mn1

Put value d in equation (1)

n1=a+(m−1)mn1

n1=a+mnm+mn1

n1=a+n1−mn1

n1=a+n1−mn1

a=mn1

Now mnth term ,

tmn=mn1+(mn−1)mn1

=mn1+1−mn1

tmn=1