How about we take \[a\text{ }and\text{ }d\]to be the initial term and the normal contrast of the A.P. separately.
Then, at that point, it given that
Along these lines, the amount of \[\left( p\text{ }+\text{ }q \right)\]terms of the A.P. is \[0.\]
If the sum of first p terms of an A.P. is equal to the sum of the first q terms, then find the sum of the first (p + q) terms.
If the sum of first p terms of an A.P. is equal to the sum of the first q terms, then find the sum of the first (p + q) terms.