Ace school

with brainly

  • Get help from millions of students
  • Learn from experts with step-by-step explanations
  • Level-up by helping others

A community for students.

The sum of first 14 terms of 1,1.4,1.8,.... is equal to the sum of first n terms of 5.6,5.8,6.0,.... , find the value of n

Mathematics
See more answers at brainly.com
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.

Join Brainly to access

this expert answer

SEE EXPERT ANSWER

To see the expert answer you'll need to create a free account at Brainly

1,1.4,1.8,.... This is in AP with first term 1 and common difference 0.4
Use sum formula of AP
14/2(a1+a14)=n/2(5.6+5.6+(n-1)*0.2)

Not the answer you are looking for?

Search for more explanations.

Ask your own question

Other answers:

14/2(1+1+13(.4))=n/2(5.6+5.6+(n-1)*0.2)
i did the first A.P and its coming 50.4
S14 =14/2 {2*1 + (14-1)0.4} = 50.4
i am stuck here
5.6,5.8,6.0,.... This is in AP with common difference 0.2 andfirt term 5.6
\[50.4=\frac{ n }{ 2 }[(2*5.6)+(n-1)*0.2]\]
stuck here
Sn=50.4 n/2 { 2*5.6 + (n-1)0.2}=50.4 n{11 - 0.2n}=100.8
2*5.6 its 11.2
11n -0.2n^2 =100.8 11n -2/10 n^2 =100.8 110n -2n^2 =1008
11.2-0.2=11
oh
110n -2n^2 =1008 2n^2-110n+1008=0 n^2-55n+504=0
how did became 110n -2n^2 =1008
|dw:1359028396466:dw|
ok
Now,n^2-55n+504=0 CAN u solve for n
n= -11.61 and n= -43.38
now what?
The Answer should come n=8...i checked the answers
n=8 is surely not the correct solution
the book says that answer is n=8
how will it come 8
Sorry I did a algebra mistake
n=8 is correct
how????? plz plz tell me
Sn=50.4 n/2 { 2*5.6 + (n-1)0.2}=50.4 n/2 {11+0.2n}=50.4 n{11+0.2n}=100.8 11n+0,2n^2=100.8 11n +2/10 n^2 =100.8 110n+2n^2=1008 55n+n^2=504 n^2+55n-504=0 n^2+(63-8)n-504=0 n^2 +63n -8n-504=0 n(n+63)-8(n+63)=0 (n-8)(n+63)=0
Now, either n-8=0 n=8 OR n+63=0 n=-63 BUT n cannot be negative So, n=8
got it?
thanks
welcome

Not the answer you are looking for?

Search for more explanations.

Ask your own question