Let 3 consecutive terms A.P is a –d, a , a + d. and the sum is 51
so, (a –d) + a + (a + d) = 51
> 3a –d + d = 51
> 3a = 51
> a = 17
The product of first and third terms is 273
So it stand for ( a –d) (a + d) = 273
>a 2 –d 2 = 273
> 172 –d 2 = 273
> 289 –d 2 = 273
> d 2 = 289 –273
> d 2 = 16
> d = (plus and minus) 4
so now put plus and minus eventually to get the third term.
