Sum of numerators divided by sum of denominators $leq$ the maximum fraction [duplicate]
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shorter proof of generalized mediant inequality?
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Let $tfrac{a_1}{b_1},dots,tfrac{a_n}{b_n}$ where $a_i,b_i>0$. How can one prove that $$frac{sum_i a_i}{sum_i b_i}leq max_j tfrac{a_j}{b_j}$$?
inequality summation
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marked as duplicate by Martin R, Shubham Johri, Community♦ Jan 5 at 21:26
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This question already has an answer here:
shorter proof of generalized mediant inequality?
2 answers
Let $tfrac{a_1}{b_1},dots,tfrac{a_n}{b_n}$ where $a_i,b_i>0$. How can one prove that $$frac{sum_i a_i}{sum_i b_i}leq max_j tfrac{a_j}{b_j}$$?
inequality summation
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marked as duplicate by Martin R, Shubham Johri, Community♦ Jan 5 at 21:26
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
add a comment |
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This question already has an answer here:
shorter proof of generalized mediant inequality?
2 answers
Let $tfrac{a_1}{b_1},dots,tfrac{a_n}{b_n}$ where $a_i,b_i>0$. How can one prove that $$frac{sum_i a_i}{sum_i b_i}leq max_j tfrac{a_j}{b_j}$$?
inequality summation
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This question already has an answer here:
shorter proof of generalized mediant inequality?
2 answers
Let $tfrac{a_1}{b_1},dots,tfrac{a_n}{b_n}$ where $a_i,b_i>0$. How can one prove that $$frac{sum_i a_i}{sum_i b_i}leq max_j tfrac{a_j}{b_j}$$?
This question already has an answer here:
shorter proof of generalized mediant inequality?
2 answers
inequality summation
inequality summation
edited Jan 5 at 21:23
Michael Rozenberg
107k1894199
107k1894199
asked Jan 5 at 21:02
Amihai ZivanAmihai Zivan
1,87411625
1,87411625
marked as duplicate by Martin R, Shubham Johri, Community♦ Jan 5 at 21:26
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
marked as duplicate by Martin R, Shubham Johri, Community♦ Jan 5 at 21:26
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Let for all $k$ we have
$$frac{a_j}{b_j}geqfrac{a_k}{b_k}$$ or
$$a_jb_kgeq a_kb_j.$$
Thus, $$a_jsum_{k=1}^nb_kgeqsum_{k=1}^na_kb_j=b_jsum_{k=1}^na_k.$$
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Let $${a_kover b_k}=max_i{a_iover b_i}$$therefore $${a_iover b_i}le {a_kover b_k}$$for any $i$ which is equivalent to $$a_ib_kle a_kb_i$$by a summation we finally have $$b_ksum_i a_ile a_ksum_i b_i$$or $${sum_i a_iover sum_i b_i}le {a_kover b_k}=max_i{a_iover b_i}$$
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Let for all $k$ we have
$$frac{a_j}{b_j}geqfrac{a_k}{b_k}$$ or
$$a_jb_kgeq a_kb_j.$$
Thus, $$a_jsum_{k=1}^nb_kgeqsum_{k=1}^na_kb_j=b_jsum_{k=1}^na_k.$$
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add a comment |
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Let for all $k$ we have
$$frac{a_j}{b_j}geqfrac{a_k}{b_k}$$ or
$$a_jb_kgeq a_kb_j.$$
Thus, $$a_jsum_{k=1}^nb_kgeqsum_{k=1}^na_kb_j=b_jsum_{k=1}^na_k.$$
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add a comment |
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Let for all $k$ we have
$$frac{a_j}{b_j}geqfrac{a_k}{b_k}$$ or
$$a_jb_kgeq a_kb_j.$$
Thus, $$a_jsum_{k=1}^nb_kgeqsum_{k=1}^na_kb_j=b_jsum_{k=1}^na_k.$$
$endgroup$
Let for all $k$ we have
$$frac{a_j}{b_j}geqfrac{a_k}{b_k}$$ or
$$a_jb_kgeq a_kb_j.$$
Thus, $$a_jsum_{k=1}^nb_kgeqsum_{k=1}^na_kb_j=b_jsum_{k=1}^na_k.$$
answered Jan 5 at 21:19
Michael RozenbergMichael Rozenberg
107k1894199
107k1894199
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Let $${a_kover b_k}=max_i{a_iover b_i}$$therefore $${a_iover b_i}le {a_kover b_k}$$for any $i$ which is equivalent to $$a_ib_kle a_kb_i$$by a summation we finally have $$b_ksum_i a_ile a_ksum_i b_i$$or $${sum_i a_iover sum_i b_i}le {a_kover b_k}=max_i{a_iover b_i}$$
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Let $${a_kover b_k}=max_i{a_iover b_i}$$therefore $${a_iover b_i}le {a_kover b_k}$$for any $i$ which is equivalent to $$a_ib_kle a_kb_i$$by a summation we finally have $$b_ksum_i a_ile a_ksum_i b_i$$or $${sum_i a_iover sum_i b_i}le {a_kover b_k}=max_i{a_iover b_i}$$
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add a comment |
$begingroup$
Let $${a_kover b_k}=max_i{a_iover b_i}$$therefore $${a_iover b_i}le {a_kover b_k}$$for any $i$ which is equivalent to $$a_ib_kle a_kb_i$$by a summation we finally have $$b_ksum_i a_ile a_ksum_i b_i$$or $${sum_i a_iover sum_i b_i}le {a_kover b_k}=max_i{a_iover b_i}$$
$endgroup$
Let $${a_kover b_k}=max_i{a_iover b_i}$$therefore $${a_iover b_i}le {a_kover b_k}$$for any $i$ which is equivalent to $$a_ib_kle a_kb_i$$by a summation we finally have $$b_ksum_i a_ile a_ksum_i b_i$$or $${sum_i a_iover sum_i b_i}le {a_kover b_k}=max_i{a_iover b_i}$$
answered Jan 5 at 21:21
Mostafa AyazMostafa Ayaz
15.7k3939
15.7k3939
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