anonymous
  • anonymous
can someone please help me... I need to pass math. what is the sum of the series? A. -220 B. -110 C. -95 D. 110
Mathematics
  • Stacey Warren - Expert brainly.com
Hey! We 've verified this expert answer for you, click below to unlock the details :)
SOLVED
At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga. Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus. Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.
chestercat
  • chestercat
I got my questions answered at brainly.com in under 10 minutes. Go to brainly.com now for free help!
anonymous
  • anonymous
\[\sum_{n-1}^{20} (5-1)\]
anonymous
  • anonymous
that 1 in the parenthesis is supposed to be an n
anonymous
  • anonymous
I did the equation but when I add all the number up I get a weird number not one that i need.

Looking for something else?

Not the answer you are looking for? Search for more explanations.

More answers

anonymous
  • anonymous
That's an arithmetic sequence because it's linear. You can use this formula |dw:1435279685117:dw|
anonymous
  • anonymous
\[\sum_{n=1}^{20} (5-n)\]?
anonymous
  • anonymous
I tried this but when I add the numbers I don't get the answer that i need... Could you help further on please.
anonymous
  • anonymous
you can do @peachpi way or you can break it in two \[\sum_{n=1}^{50}5-\sum_{n=1}^{20}n\]
anonymous
  • anonymous
oops \[\sum_{n=1}^{20}5-\sum_{n=1}^{20}n\]
anonymous
  • anonymous
I did 5 -1 -1 5 - 2 - 1 5 - 3 - 1 and so on
anonymous
  • anonymous
the first summation is \(20\times 5\) and for the second one it is \[\frac{20\times 21}{2}\]
anonymous
  • anonymous
use @peachpi formula, you do not want to add up twenty numbers
anonymous
  • anonymous
okay I will try
anonymous
  • anonymous
@peachpi can you write you formula out I dont really understand it
anonymous
  • anonymous
your formula is 5 -n. The sum goes from 1 to 20, so plug them in. What do you get when you sub in 1 for n? What do you get when you sub in 20 for n?
anonymous
  • anonymous
5 - 1 = 4 5 - 20 = -15
anonymous
  • anonymous
right...
anonymous
  • anonymous
|dw:1435280659076:dw|
anonymous
  • anonymous
-11
anonymous
  • anonymous
5*-11
anonymous
  • anonymous
-55
anonymous
  • anonymous
\[\frac{20}{2}\neq 5\]
anonymous
  • anonymous
10
anonymous
  • anonymous
@satellite73
anonymous
  • anonymous
so then 10 * -11
anonymous
  • anonymous
-110
anonymous
  • anonymous
yes
anonymous
  • anonymous
thank you so much.

Looking for something else?

Not the answer you are looking for? Search for more explanations.