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Answers
Answer:
32n+54
Step-by-step explanation:
(7nx4n)+(7nx27) +(1x4n) +(1x27)
(28n+4n)+(27+27)
32n+54
Answer:
am₁ : am₂ = P = 14m-6:8m+223
Step-by-step explanation:
Given:- if the ratio of first n term of two A.P.S is (7n+1 ): (4n+27)
Find :- The ratio of their mth term .
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Let a₁ , a₂ and d₁ d₂ be the first term and common difference of two A. P. S
Sn₁ = n/2{2a₁ +(n-1)d₁ }
Sn₂ = n/2( 2a₂ + (n-1)d₂}
But , sn₁ /sn₂ = 7n+1/4n+27
∴ 2a₁ + (n-1)d₁ /2a₂ + (n-1)d₂ = 7n+1/4n+27 _____(1)
As we know that , to find nth term
it's standard formula is a+(n-1)d
So dividing by 2 in eq(1)'s numerator and denomenator .
We get , a₁ + (n-1)/2*d₁ /a₂+(n-1)/2*d₂ = 7n+1/4n+27 _____(2)
Now, We have to find mth term of each APS
am₁ = a₁+ (m ₁-1)d₁
am₁ = a₁+ (m ₁-1)d₁ am₂ = a₂ + (m₂-1)d₂
Comparing am₁ to a₁+(n-1)/2 *d₁
we get , n-1/2= m-1
n = 2m-1
Now putting n = 2m -1
⟹ a₁ +(m-1)d₁ /a₂ + (m-1)d₂ = 7(2m-1)+1/4(2m-1) +27 = 14m-6/8m+23
∴am₁ /am₂ = 14m-6/8m+23
So ,P = 14m-6/8m+23 Answer..