(n^4 - 1) = (n^2 - 1) (n^2 +1) = (n - 1) (n + 1) (n^2 + 1)
First term a1 = 6+5 = 11
second term = 12+5 = 17
common difference = 6
Sum of n terms:-
Sn = (n/2) [ 2a1 + d(n - 1)]
Sum of 30 terms:-
S30 = (30/2)[ 2*11 + 6(30-1)]
= 15 * ( 22 + 174)
= 15 * 196
= 2940 Answer
The correct answer is b because of the answers given you start to graph it gives you the answer.
The answer would be 0 because 0 is a perfect square. Hope this helps :)
C, because it says ABOVE 25,000 feet :)
