Answered

Welcome to Westonci.ca, the place where your questions are answered by a community of knowledgeable contributors. Join our Q&A platform to connect with experts dedicated to providing precise answers to your questions in different areas. Our platform provides a seamless experience for finding reliable answers from a network of experienced professionals.

given the arithmetic sequence 8, 5, 2, -1,..., find S20

Sagot :

mumsy
The formula to find any term of an an arithmetic sequence is given by
[tex]a _{n} [/tex]=[tex]a _{1} [/tex]=(n-1)d,
where we have first term [tex] a_{1} [/tex]=8, 
and d which is the common difference , and n is the term we need to find (in our case is 20)
the difference d=3, as you see each number is the previous minus 3
for S20=8+(20-1)*(-3)=8+(19)*(-3)=8-57=-49
S20=-49, this the 20th term
Thanks for using our service. We're always here to provide accurate and up-to-date answers to all your queries. Thank you for visiting. Our goal is to provide the most accurate answers for all your informational needs. Come back soon. Thank you for choosing Westonci.ca as your information source. We look forward to your next visit.