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Category: Algebra

Prove-or-disprove-that-for-even-positive-n-2-k-1-n-2-1-1-k-n-k-1-n-2-n-n-2-2-2-

Question Number 2441 by Yozzi last updated on 20/Nov/15 $${Prove}\:{or}\:{disprove}\:{that}\:,\:{for}\:{even}\: \\ $$$${positive}\:{n}, \\ $$$$\mathrm{2}×\underset{{k}=\mathrm{1}} {\overset{\frac{{n}}{\mathrm{2}}−\mathrm{1}} {\sum}}\left(−\mathrm{1}\right)^{{k}} \begin{pmatrix}{{n}}\\{{k}}\end{pmatrix}+\left(−\mathrm{1}\right)^{\left({n}/\mathrm{2}\right)} \frac{{n}!}{\left(\left({n}/\mathrm{2}\right)!\right)^{\mathrm{2}} }=−\mathrm{2} \\ $$ Commented by Rasheed Soomro…

find-x-in-terms-of-a-1-x-2x-x-2-1-x-2x-x-2-a-3-2-x-x-2-x-x-

Question Number 133469 by Eric002 last updated on 22/Feb/21 $${find}\:{x}\:{in}\:{terms}\:{of}\:{a} \\ $$$$\frac{\mathrm{1}+{x}−\sqrt{\mathrm{2}{x}+{x}^{\mathrm{2}} }}{\mathrm{1}+{x}+\sqrt{\mathrm{2}{x}+{x}^{\mathrm{2}} }}={a}^{\mathrm{3}} \frac{\sqrt{\mathrm{2}+{x}}+\sqrt{{x}}}{\:\sqrt{\mathrm{2}+{x}}−\sqrt{{x}}} \\ $$ Answered by EDWIN88 last updated on 22/Feb/21 $$\frac{\left[\left(\mathrm{1}+\mathrm{x}\right)−\sqrt{\mathrm{2x}+\mathrm{x}^{\mathrm{2}}…

if-x-2-5x-9-0-then-x-

Question Number 2304 by Ashis last updated on 14/Nov/15 $${if}\:\:{x}^{\mathrm{2}} +\mathrm{5}{x}−\mathrm{9}=\:\mathrm{0}\:\:{then}\:{x}=? \\ $$ Answered by prakash jain last updated on 14/Nov/15 $${x}^{\mathrm{2}} +\mathrm{5}{x}−\mathrm{9} \\ $$$${x}=\frac{−\mathrm{5}\pm\sqrt{\left(−\mathrm{5}\right)^{\mathrm{2}}…

Question-67826

Question Number 67826 by peter frank last updated on 31/Aug/19 Commented by gunawan last updated on 01/Sep/19 $${x}=\mathrm{1}+{a}+{a}^{\mathrm{2}} +{a}^{\mathrm{3}} +.. \\ $$$${x}=\frac{\mathrm{1}}{\mathrm{1}−{a}}\:\Rightarrow\mathrm{1}−\:{a}=\frac{\mathrm{1}}{{x}}\Rightarrow\:{a}=\mathrm{1}−\frac{\mathrm{1}}{{x}}=\frac{{x}−\mathrm{1}}{{x}} \\ $$$${y}=\mathrm{1}+{b}+{b}^{\mathrm{2}} +{b}^{\mathrm{3}}…

y-x-5-ax-4-bx-3-cx-2-dx-e-If-we-let-x-t-h-can-we-find-h-in-terms-of-a-b-c-d-e-such-that-y-t-R-t-2-pt-q-t-2-s-this-means-two-roots-are-of-opposite-sign-of-course-its-possible-by-shifting-the

Question Number 67819 by ajfour last updated on 31/Aug/19 $${y}={x}^{\mathrm{5}} +{ax}^{\mathrm{4}} +{bx}^{\mathrm{3}} +{cx}^{\mathrm{2}} +{dx}+{e} \\ $$$${If}\:{we}\:{let}\:{x}={t}+{h} \\ $$$${can}\:{we}\:{find}\:{h}\:{in}\:{terms}\:{of}\:{a},{b},{c},{d},{e} \\ $$$${such}\:{that} \\ $$$${y}=\left({t}+{R}\right)\left({t}^{\mathrm{2}} +{pt}+{q}\right)\left({t}^{\mathrm{2}} +{s}\right) \\…

Sum-to-n-terms-1-1-1-1-2-1-1-2-3-

Question Number 2273 by RasheedAhmad last updated on 12/Nov/15 $${Sum}\:{to}\:{n}\:{terms}. \\ $$$$\frac{\mathrm{1}}{\mathrm{1}}+\frac{\mathrm{1}}{\mathrm{1}+\mathrm{2}}+\frac{\mathrm{1}}{\mathrm{1}+\mathrm{2}+\mathrm{3}}… \\ $$ Answered by Yozzi last updated on 12/Nov/15 $${For}\:{an}\:{A}.{P}\:{with}\:{first}\:{term}\:{a}\:{and} \\ $$$${common}\:{difference}\:{d},\:{its}\:{sum}\:{to}\:{n} \\…