Answer:The sequence is an arithmetic sequence with a common difference of -6. The formula for the sum of an arithmetic series is: S = (n/2)(a + l) where: - S is the sum of the series- n is the number of terms- a is the first term- l is the last term In this case: - n = 10- a = 19- l = 1 - (9 * 6) = -53 Therefore: S = (10/2)(19 - 53) = 5(-34) = -170Step-by-step explanation:ez