Find the sum of the arithmetic series in which a1 = - 68, d = - 3, and n = 20.

Sum = - 1930

Step-by-step explanation:

Sum of an arithmetic series;

; Sum = n/2[ 2a1 + (n - 1) d]

Then substitute into the equation above

; Sum = 20/2 [ 2 (-68) + (19) - 3 ]

; Sum = 10 [ - 136 - 57 ]

Therefore the sum of the arithmetic series

is ...; - 1930