Answer:
d=-4 and a=10
Step-by-step explanation:
The sum of a arithmetic sequence is given by (n/2)*(2a+(n-1)d). Comparing coefficients with the given Sn, we have; a-d/2=12 and d/2=-2, d=-4 and a=10.
Not all prime numbers are odd, 2 is not odd and it's a prime number
I think that you should try to involve yourself in their interests. Find a way to play with them because, as it seems, you want to maintain a friendship with this person, but want to be more involved in their life. I hope this helps <3

let's find the value of added tax :
The value of added tax (VAT) = ₹ 3277.5