Answer:
n²-5n
Explanation:
The sum of the nth term is expressed as;
Sn =n/2[2a+(n-1)d]
Given
a, = -4; d = 2; n = 16
Sn = n/2[2(-4)+(n-1)2]
Sn =n/2[-8+2n-2]
Sn = n/2[2n-10]
Hence the sum of the nth term is 2n²-10n/2
2n(n-5)/2
= n(n-5)
= n²-5n
The sum of the nth term is n²-5n