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 2 years ago
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
 2 years ago
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

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sauravshakya
 2 years ago
Best ResponseYou've already chosen the best response.11,1.4,1.8,.... This is in AP with first term 1 and common difference 0.4

sauravshakya
 2 years ago
Best ResponseYou've already chosen the best response.1Use sum formula of AP

amoodarya
 2 years ago
Best ResponseYou've already chosen the best response.014/2(a1+a14)=n/2(5.6+5.6+(n1)*0.2)

amoodarya
 2 years ago
Best ResponseYou've already chosen the best response.014/2(1+1+13(.4))=n/2(5.6+5.6+(n1)*0.2)

koli123able
 2 years ago
Best ResponseYou've already chosen the best response.0i did the first A.P and its coming 50.4

sauravshakya
 2 years ago
Best ResponseYou've already chosen the best response.1S14 =14/2 {2*1 + (141)0.4} = 50.4

sauravshakya
 2 years ago
Best ResponseYou've already chosen the best response.15.6,5.8,6.0,.... This is in AP with common difference 0.2 andfirt term 5.6

koli123able
 2 years ago
Best ResponseYou've already chosen the best response.0\[50.4=\frac{ n }{ 2 }[(2*5.6)+(n1)*0.2]\]

sauravshakya
 2 years ago
Best ResponseYou've already chosen the best response.1Sn=50.4 n/2 { 2*5.6 + (n1)0.2}=50.4 n{11  0.2n}=100.8

sauravshakya
 2 years ago
Best ResponseYou've already chosen the best response.111n 0.2n^2 =100.8 11n 2/10 n^2 =100.8 110n 2n^2 =1008

sauravshakya
 2 years ago
Best ResponseYou've already chosen the best response.1110n 2n^2 =1008 2n^2110n+1008=0 n^255n+504=0

koli123able
 2 years ago
Best ResponseYou've already chosen the best response.0how did became 110n 2n^2 =1008

sauravshakya
 2 years ago
Best ResponseYou've already chosen the best response.1dw:1359028396466:dw

sauravshakya
 2 years ago
Best ResponseYou've already chosen the best response.1Now,n^255n+504=0 CAN u solve for n

koli123able
 2 years ago
Best ResponseYou've already chosen the best response.0n= 11.61 and n= 43.38

koli123able
 2 years ago
Best ResponseYou've already chosen the best response.0The Answer should come n=8...i checked the answers

sauravshakya
 2 years ago
Best ResponseYou've already chosen the best response.1n=8 is surely not the correct solution

koli123able
 2 years ago
Best ResponseYou've already chosen the best response.0the book says that answer is n=8

sauravshakya
 2 years ago
Best ResponseYou've already chosen the best response.1Sorry I did a algebra mistake

koli123able
 2 years ago
Best ResponseYou've already chosen the best response.0how????? plz plz tell me

sauravshakya
 2 years ago
Best ResponseYou've already chosen the best response.1Sn=50.4 n/2 { 2*5.6 + (n1)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+55n504=0 n^2+(638)n504=0 n^2 +63n 8n504=0 n(n+63)8(n+63)=0 (n8)(n+63)=0

sauravshakya
 2 years ago
Best ResponseYou've already chosen the best response.1Now, either n8=0 n=8 OR n+63=0 n=63 BUT n cannot be negative So, n=8
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