In an A.P.(arithmatic progression) if Sn = 3n^ 2 + 5n and ak = 164, then find the value of k

explain me in above image marked part should be +or -

in Other Math Topics by Level 1 User (300 points)

Your answer

Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
To avoid this verification in future, please log in or register.

1 Answer

The sign is minus because -(3(n-1)²+5(n-1))=-3(n-1)²-5(n-1) applying the distributive property to the minus sign. The distributive property crops up in the following lines, too, so the logic is correct.

by Top Rated User (1.2m points)

Related questions

1 answer
3k-4p=ak-9p, solve for k
asked Sep 15, 2013 in Algebra 1 Answers by anonymous | 772 views
1 answer
For A.P if a=6,S4=105 then prove that Sn:Sn-3=(n+3):(n-3).
asked Feb 24, 2014 in Algebra 2 Answers by L.B.Yadav | 804 views
1 answer
if 3n+5=5n-3, what is n
asked Nov 13, 2012 in Pre-Algebra Answers by Katieisawesome Level 1 User (140 points) | 856 views
1 answer
if 3n+5=5n-3, what is n
asked Nov 13, 2012 in Pre-Algebra Answers by Katieisawesome Level 1 User (140 points) | 1.2k views
1 answer
What does n = in 5n+3=3n+11
asked Feb 12, 2013 in Pre-Algebra Answers by anonymous | 822 views
1 answer
In an AP, given an=4, d=2, sn=-14, Find n and a.
asked Feb 15, 2016 in Other Math Topics by anonymous | 1.7k views
1 answer
5n^2-3n-15=10
asked May 1, 2020 in Algebra 1 Answers by anonymous | 540 views
1 answer
5n^2-3n-15=10
asked Aug 17, 2017 in Algebra 1 Answers by anonymous | 507 views
1 answer
5n- (-3n)+6 simplify
asked Aug 27, 2014 in Geometry Answers by Jordan | 708 views
1 answer
How to solve(2m-3n)(4m+n)+(3n-2m)(2m-5n)
asked Mar 29, 2013 in Algebra 2 Answers by anonymous | 2.2k views
1 answer
missing factor: 36m^5n^7= (2m^3n)(6n^5)(?)
asked Mar 10, 2013 in Algebra 1 Answers by anonymous | 727 views
0 answers
9 + 3n 3 or 5n < 30
asked Dec 12, 2012 in Trigonometry Answers by anonymous | 652 views
Welcome to MathHomeworkAnswers.org, where students, teachers and math enthusiasts can ask and answer any math question. Get help and answers to any math problem including algebra, trigonometry, geometry, calculus, trigonometry, fractions, solving expression, simplifying expressions and more. Get answers to math questions. Help is always 100% free!

Most popular questions within the last 3000 days

  1. 50+50-25X0+2+2= (19)
  2. it takes 10 road workers 5 days to complete a road repair when working 2 hours a day.Working at the same pace,how many days will it take 2 people working 5 hours a day to finish it? (3)
  3. Solve 15 -1(12÷4+1)? (4)
  4. 8:4(5+2) (3)
  5. How can i represent 1/3; 3/3; 7/3; 10/3 and 15/3 on a number line? (1)

Most popular tags

87,516 questions
100,279 answers
2,420 comments
732,348 users