Question

If the sum of first k term of an



a.P is 3k square - k and its common difference is 6 then what is its first term

Answer 1

Answer:

2-3k

Step-by-step explanation:

S=k/2 (2a+(k-1)d)

3k²-k=k/2 (2a+(k-1)6)

6k²-2k=2ak+6k²-6k

4k-6k²=2ak

a=2 - 3k