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Category: Algebra

Show-that-the-sum-of-odd-coefficients-in-the-expansion-of-1-2x-3x-2-1025-is-an-even-integer-

Question Number 22392 by Tinkutara last updated on 17/Oct/17 $$\mathrm{Show}\:\mathrm{that}\:\mathrm{the}\:\mathrm{sum}\:\mathrm{of}\:\mathrm{odd}\:\mathrm{coefficients} \\ $$$$\mathrm{in}\:\mathrm{the}\:\mathrm{expansion}\:\mathrm{of}\:\left(\mathrm{1}\:+\:\mathrm{2}{x}\:−\:\mathrm{3}{x}^{\mathrm{2}} \right)^{\mathrm{1025}} \\ $$$$\mathrm{is}\:\mathrm{an}\:\mathrm{even}\:\mathrm{integer}. \\ $$ Terms of Service Privacy Policy Contact: info@tinkutara.com

Prove-that-n-C-0-n-n-C-1-n-1-n-C-2-n-2-1-n-n-C-n-2n-1-n-2n-C-n-

Question Number 22394 by Tinkutara last updated on 17/Oct/17 $$\mathrm{Prove}\:\mathrm{that}\::\:\frac{\:^{{n}} {C}_{\mathrm{0}} }{{n}}−\frac{\:^{{n}} {C}_{\mathrm{1}} }{{n}+\mathrm{1}}+\frac{\:^{{n}} {C}_{\mathrm{2}} }{{n}+\mathrm{2}}−…+\left(−\mathrm{1}\right)^{{n}} .\frac{\:^{{n}} {C}_{{n}} }{\mathrm{2}{n}}=\frac{\mathrm{1}}{{n}.^{\mathrm{2}{n}} {C}_{{n}} } \\ $$ Terms of…

For-each-positive-integer-n-define-a-n-20-n-2-and-d-n-gcd-a-n-a-n-1-Find-the-set-of-all-values-that-are-taken-by-d-n-and-show-by-examples-that-each-of-these-values-are-attained-

Question Number 22379 by Tinkutara last updated on 16/Oct/17 $$\mathrm{For}\:\mathrm{each}\:\mathrm{positive}\:\mathrm{integer}\:{n},\:\mathrm{define}\:{a}_{{n}} \:= \\ $$$$\mathrm{20}\:+\:{n}^{\mathrm{2}} ,\:\mathrm{and}\:{d}_{{n}} \:=\:{gcd}\left({a}_{{n}} ,\:{a}_{{n}+\mathrm{1}} \right).\:\mathrm{Find} \\ $$$$\mathrm{the}\:\mathrm{set}\:\mathrm{of}\:\mathrm{all}\:\mathrm{values}\:\mathrm{that}\:\mathrm{are}\:\mathrm{taken}\:\mathrm{by} \\ $$$${d}_{{n}} \:\mathrm{and}\:\mathrm{show}\:\mathrm{by}\:\mathrm{examples}\:\mathrm{that}\:\mathrm{each}\:\mathrm{of} \\ $$$$\mathrm{these}\:\mathrm{values}\:\mathrm{are}\:\mathrm{attained}. \\…

L-1-s-s-2-12s-40-

Question Number 153446 by mathdanisur last updated on 07/Sep/21 $$\mathrm{L}^{−\mathrm{1}} \left\{\frac{\mathrm{s}}{\mathrm{s}^{\mathrm{2}} \:-\:\mathrm{12s}\:+\:\mathrm{40}}\right\}\:=\:? \\ $$ Commented by alisiao last updated on 07/Sep/21 $$=\:{L}^{−\mathrm{1}} \:\left\{\frac{\left({s}−\mathrm{6}\right)}{\left({s}−\mathrm{6}\right)^{\mathrm{2}} +\mathrm{4}}\:+\:\frac{\mathrm{6}}{\left({s}−\mathrm{6}\right)^{\mathrm{2}} +\mathrm{4}}\right\}…

Question-87886

Question Number 87886 by TawaTawa1 last updated on 06/Apr/20 Commented by jagoll last updated on 07/Apr/20 $$\mathrm{x}^{\mathrm{2}} −\mathrm{4x}+\mathrm{1}\:=\:\mathrm{0} \\ $$$$\left(\mathrm{x}−\mathrm{2}\right)^{\mathrm{2}} −\mathrm{3}=\mathrm{0} \\ $$$$\mathrm{x}\:=\:\mathrm{2}\:\pm\:\sqrt{\mathrm{3}}\: \\ $$$$\mathrm{y}^{\mathrm{2}}…

If-a-b-c-d-0-prove-that-a-3-bc-b-3-cd-c-3-da-d-3-ab-a-b-c-d-

Question Number 153412 by mathdanisur last updated on 07/Sep/21 $$\mathrm{If}\:\:\:\mathrm{a};\mathrm{b};\mathrm{c};\mathrm{d}\in\left(\mathrm{0};\infty\right)\:\:\mathrm{prove}\:\mathrm{that}: \\ $$$$\frac{\mathrm{a}^{\mathrm{3}} }{\mathrm{bc}}\:+\:\frac{\mathrm{b}^{\mathrm{3}} }{\mathrm{cd}}\:+\:\frac{\mathrm{c}^{\mathrm{3}} }{\mathrm{da}}\:+\:\frac{\mathrm{d}^{\mathrm{3}} }{\mathrm{ab}}\:\geqslant\:\mathrm{a}\:+\:\mathrm{b}\:+\:\mathrm{c}\:+\:\mathrm{d} \\ $$ Answered by puissant last updated on 07/Sep/21…

Question-153407

Question Number 153407 by liberty last updated on 07/Sep/21 Answered by Rasheed.Sindhi last updated on 08/Sep/21 $${x}\equiv\mathrm{2}\:\left({mod}\:\mathrm{5}\right)……..\left({i}\right) \\ $$$${x}\equiv\mathrm{1}\:\left({mod}\:\mathrm{3}\right)……..\left({ii}\right) \\ $$$${x}\equiv\mathrm{6}\:\left({mod}\:\mathrm{14}\right)……\left({iii}\right) \\ $$$$\underset{\underset{} {−}} {{x}\equiv\mathrm{5}\underline{\:\left({mod}\:\mathrm{11}\right)…….\left({iv}\right)\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:}\:\:\:\:\:\:\:\:\:}\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:…