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Category: Algebra

solve-1-n-2-n-n-2-4n-

Question Number 171742 by Mikenice last updated on 20/Jun/22 $${solve}:\:\left(\mathrm{1}+{n}\right)!+\mathrm{2}\left({n}\right)!=\left({n}+\mathrm{2}\right)!−\mathrm{4}{n}! \\ $$ Commented by kaivan.ahmadi last updated on 20/Jun/22 $$\left({n}+\mathrm{2}\right)!−\left({n}+\mathrm{1}\right)!−\mathrm{6}{n}!=\mathrm{0} \\ $$$${n}!\left[\left({n}+\mathrm{1}\right)\left({n}+\mathrm{2}\right)−\left({n}+\mathrm{1}\right)−\mathrm{6}\right]=\mathrm{0} \\ $$$$\Rightarrow{n}^{\mathrm{2}} +\mathrm{3}{n}+\mathrm{2}−{n}−\mathrm{1}−\mathrm{6}=\mathrm{0}\Rightarrow…

solve-12-x-2-4-x-find-x-

Question Number 171743 by Mikenice last updated on 20/Jun/22 $${solve}:\:\mathrm{12}^{{x}−\mathrm{2}} =\mathrm{4}^{{x}} ,\:{find}\:{x} \\ $$ Commented by kaivan.ahmadi last updated on 20/Jun/22 $$\mathrm{3}^{{x}−\mathrm{2}} ×\mathrm{4}^{{x}−\mathrm{2}} =\mathrm{4}^{{x}} \Rightarrow\mathrm{3}^{{x}−\mathrm{2}}…

If-20-men-can-lay-36m-of-a-pipe-in-8-hours-How-long-would-25-men-take-to-lay-the-next-54m-of-the-pipe-

Question Number 106176 by john santu last updated on 03/Aug/20 $$\mathrm{If}\:\mathrm{20}\:\mathrm{men}\:\mathrm{can}\:\mathrm{lay}\:\mathrm{36m}\:\mathrm{of}\:\mathrm{a}\:\mathrm{pipe} \\ $$$$\mathrm{in}\:\mathrm{8}\:\mathrm{hours}.\:\mathrm{How}\:\mathrm{long}\:\mathrm{would}\:\mathrm{25} \\ $$$$\mathrm{men}\:\mathrm{take}\:\mathrm{to}\:\mathrm{lay}\:\mathrm{the}\:\mathrm{next}\:\mathrm{54m}\:\mathrm{of} \\ $$$$\mathrm{the}\:\mathrm{pipe}? \\ $$ Commented by john santu last updated…

Given-xy-1-x-1-y-9-x-y-20-where-x-gt-y-find-the-value-of-x-y-y-x-

Question Number 106156 by bemath last updated on 03/Aug/20 $$\mathrm{Given}\:\begin{cases}{\sqrt{\mathrm{xy}}\:+\frac{\mathrm{1}}{\:\sqrt{\mathrm{x}}}\:+\frac{\mathrm{1}}{\:\sqrt{\mathrm{y}}}\:=\mathrm{9}}\\{\sqrt{\mathrm{x}}+\sqrt{\mathrm{y}}\:=\:\mathrm{20}}\end{cases} \\ $$$$\mathrm{where}\:\mathrm{x}\:>\:\mathrm{y}.\:\mathrm{find}\:\mathrm{the}\:\mathrm{value}\:\mathrm{of} \\ $$$$\mathrm{x}\sqrt{\mathrm{y}}\:−\mathrm{y}\sqrt{\mathrm{x}}\:. \\ $$ Commented by bemath last updated on 03/Aug/20 $$\mathrm{let}\:\sqrt{\mathrm{x}}\:=\:\mathrm{a}\:\&\:\sqrt{\mathrm{y}}\:=\:\flat\: \\…

In-ABC-AA-BB-CC-cevians-AA-BB-CC-P-Prove-that-min-APC-BPA-CPB-min-APB-BPC-CPA-Rr-3-2-

Question Number 171688 by Shrinava last updated on 20/Jun/22 $$\mathrm{In}\:\:\bigtriangleup\mathrm{ABC} \\ $$$$\mathrm{AA}^{'} \:,\:\mathrm{BB}^{'} \:,\:\mathrm{CC}^{'} \:-\:\mathrm{cevians} \\ $$$$\mathrm{AA}^{'} \:\cap\:\mathrm{BB}^{'} \:\cap\:\mathrm{CC}^{'} \:=\:\left\{\mathrm{P}\right\} \\ $$$$\mathrm{Prove}\:\mathrm{that}: \\ $$$$\mathrm{min}\left(\left[\mathrm{APC}^{'} \right],\left[\mathrm{BPA}^{'}…

Question-171681

Question Number 171681 by Shrinava last updated on 19/Jun/22 Answered by mindispower last updated on 19/Jun/22 $${We}\:{Have}\:{Ln}\:{increase}\:{function}\:\:{witch}\:{is}\:{octave}\:{function} \\ $$$$\Leftrightarrow{aln}\left({cot}\left({A}\right)\right)+{bln}\left({cot}\left({B}\right)\right)+{cln}\left({cot}\left({C}\right)\right)\leqslant\left({a}+{b}+{c}\right){ln}\left(\frac{\mathrm{3}{R}}{{a}+{b}+{c}}\right) \\ $$$$\frac{\mathrm{1}}{{a}+{b}+{c}}\left({aln}\left({cot}\left({A}\right)\right)+{bln}\left({Cot}\left({B}\right)\right)+{cln}\left({cot}\left({C}\right)\right)\leqslant\right. \\ $$$${ln}\left(\frac{{acot}\left({A}\right)}{{a}+{b}+{c}}+\frac{{bcot}\left({B}\right)}{{a}+{b}+{c}}+\frac{{cCot}\left({C}\right)}{{a}+{b}+{c}}\right)….{E} \\ $$$$={ln}\left(\frac{\mathrm{1}}{{a}+{b}+{c}}\left(\frac{{acos}\left({A}\right)}{{sin}\left({A}\right)}+\frac{{bCos}\left({B}\right)}{{sin}\left({B}\right)}+\frac{{cCos}\left({C}\right)}{{sin}\left({C}\right)}\right)\right.…