anonymous
  • anonymous
Please help me. I will medal & fan!!!!!!!!** :) If the nth term of a sequence is 2n + 4, what is the sum of the first n terms? A.) n(n+1)+4n B.) n(n+1)/2 +n C.) n(2n+4) D.) n(n+1)(2n+1) /6 + 2n(n+1) E.) 2n(n+1)/n
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.
katieb
  • katieb
I got my questions answered at brainly.com in under 10 minutes. Go to brainly.com now for free help!
Michele_Laino
  • Michele_Laino
the first term is: \[{a_1} = 2 \times 1 + 4 = ...?\]
anonymous
  • anonymous
I would just plug that in?
Michele_Laino
  • Michele_Laino
the first term is given by replacing n with 1 into your formula

Looking for something else?

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

More answers

Michele_Laino
  • Michele_Laino
the requested sum S is given by the subsequent formula: \[S = \frac{{{a_1} + {a_n}}}{2} \times n\]
Michele_Laino
  • Michele_Laino
what is a_1?
anonymous
  • anonymous
8?
Michele_Laino
  • Michele_Laino
hint: \[\large {a_1} = 2 \times 1 + 4 = 2 + 4 = ...?\]
anonymous
  • anonymous
I'm just a numskull and don't understand any of this. I thank you for time and effort. I will just guess at this point... Thank you, though. :)
Michele_Laino
  • Michele_Laino
please wait
Michele_Laino
  • Michele_Laino
the first term is a1=6 right?
Michele_Laino
  • Michele_Laino
now we have to substitute so we can write: \[\large \begin{gathered} S = \frac{{{a_1} + {a_n}}}{2} \times n = \frac{{6 + 2n + 4}}{2} \times n = \frac{{10 + 2n}}{2} \times n = \hfill \\ \hfill \\ = \left( {5 + n} \right)n = 5n + {n^2} \hfill \\ \end{gathered} \]
Michele_Laino
  • Michele_Laino
now we have this: \[\Large n\left( {n + 1} \right) + 4n = {n^2} + n + 4n = {n^2} + 5n\]
anonymous
  • anonymous
n(2n+4) ?
Michele_Laino
  • Michele_Laino
I think that it is: n(n+1)+4n
anonymous
  • anonymous
no it's n(n+1)+4n ??
Michele_Laino
  • Michele_Laino
that's right!
anonymous
  • anonymous
yay!! thank you!!
Michele_Laino
  • Michele_Laino
:)

Looking for something else?

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