If the first, second and the last terms of an A.P. are a,b,c respectively, then the sum of the A.P. is

The first, second and last terms of an A.P. are a, b, c respectively, then the sum to first n terms is

If the first second and the last terms of an A.P are a,band 2a , respectively, then its sum is

If the first and the last terms of an A.P. are -4 and 146 respectively and the sum of this A.P. is 7171 then its common difference is

The first , second and the last terms of an A.P. are a ,b , c respectively. Prove that the sum is ((a+c)(b+c-2a))/(2(b-a)) .

If the first, second and last terms of A.P. be a, b, and c respectively, show that the sum of all terms of the A.P. is ((a+c)(b+c-2a))/(2(b-a)) .

The first,second and the last terms of an A.P. are a,b,c respectively.Prove that the sum is (a+c)(b+c-2a)hline2(b-a)

First , second and middle terms of an A.P. are a,b,c respectively . The sum of AP is :

If the first,second and last term of an AP are a,b and 2a respectively,its sum is

The first, second and middle terms of an A.P. are a, b, c, respectively. Then the sum of all terms of the A.P. is