Question 1127068
<br>
The common difference between terms is 5 (we don't need to worry about the sign for this part of the problem).<br>
The difference between the first and last terms, divided by the common difference, tells us how many terms there are AFTER THE FIRST ONE.  So the number of terms is<br>
(difference between first and last) divided by (common difference), PLUS 1.<br>
{{{(abs(-239-6)/5)+1 = 89+1 = 90}}}<br>
ANSWER (i): There are 90 terms in the sequence.<br>
The sum of the terms is the number of terms, multiplied by the average; the average of all the terms in an arithmetic sequence is the average of the first and last terms.<br>
average = (6-239)/2 = -233/2
number of terms = 90
sum = 90*(-233/2) = -10485<br>
ANSWER (ii): The sum of the terms is -10485.