Same thing ine just a bit neater/ nicer
if you know that -2222 if term one and difference is 17 i.e. next term is -2205 etc. You know 100 terms on is +1700 basically fudge the way by doing -2222/17 to work out how many 17s add to get close to 0 .
2) Formula : nth term =a + d(n-1)
U need when goes over 0
So solve by 0>a+d(n-1)
0> -2222+17(n-1)
Then that should give u no terms when is 0. Next whole
Number of N (I assume answer will be decimal) is term which exceeds formula.
Plug that N back into the formula or just add 17 that many times.