Question Number 179198 by Acem last updated on 26/Oct/22
Commented by Acem last updated on 26/Oct/22
$${Area}_{{Square}} ? \\ $$
Commented by Acem last updated on 26/Oct/22
$${All}\:{the}\:{methods}\:{have}\:{good}\:{ideas},\:{Thanks}\:{for}\:{all} \\ $$
Answered by cortano1 last updated on 26/Oct/22
$$\:\frac{\mathrm{5}}{\mathrm{x}}\:=\:\frac{\mathrm{x}}{\mathrm{20}}\:\Rightarrow\mathrm{x}^{\mathrm{2}} =\mathrm{100}\: \\ $$$$\: \\ $$
Commented by Rasheed.Sindhi last updated on 26/Oct/22
$$\mathcal{E}{fficient}\:{way}! \\ $$
Commented by Acem last updated on 26/Oct/22
$${Very}\:{well}! \\ $$
Answered by Rasheed.Sindhi last updated on 26/Oct/22
$$\boldsymbol{\mathcal{T}{hrough}}\:\boldsymbol{\mathcal{A}{reas}}…. \\ $$$$\blacktriangle=\frac{\mathrm{1}}{\mathrm{2}}\left({a}+\mathrm{5}\right)\left({a}+\mathrm{20}\right) \\ $$$$\blacktriangle=\frac{\mathrm{1}}{\mathrm{2}}\left({a}\right)\left(\mathrm{20}\right)\:\:\:,\:\:\:\blacktriangle=\frac{\mathrm{1}}{\mathrm{2}}\left(\mathrm{5}\right)\left({a}\right) \\ $$$$\blacksquare=\blacktriangle−\blacktriangle−\blacktriangle \\ $$$$\:\:\:=\frac{\mathrm{1}}{\mathrm{2}}\left({a}+\mathrm{5}\right)\left({a}+\mathrm{20}\right)−\frac{\mathrm{1}}{\mathrm{2}}\left({a}\right)\left(\mathrm{20}\right)−\frac{\mathrm{1}}{\mathrm{2}}\left(\mathrm{5}\right)\left({a}\right) \\ $$$$\:\:=\frac{\mathrm{1}}{\mathrm{2}}\left({a}^{\mathrm{2}} +\mathrm{25}{a}+\mathrm{100}−\mathrm{20}{a}−\mathrm{5}{a}\right) \\ $$$$\mathrm{2}\blacksquare=\blacksquare+\mathrm{100}\:\:\:\:\left[\because\:{a}^{\mathrm{2}} =\blacksquare\right] \\ $$$$\blacksquare=\mathrm{100} \\ $$
Commented by Acem last updated on 26/Oct/22
$${Very}\:{nice}\:{idea}\:{too} \\ $$
Answered by Rasheed.Sindhi last updated on 26/Oct/22
$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\underset{\boldsymbol{\mathrm{Hypotenuses}}} {\mathrm{W}\boldsymbol{\mathrm{ith}}\:\boldsymbol{\mathrm{the}}\:\boldsymbol{\mathrm{help}}\:\boldsymbol{\mathrm{of}}} \\ $$$$\mathrm{H}=\sqrt{\left({a}+\mathrm{5}\right)^{\mathrm{2}} +\left({a}+\mathrm{20}\right)^{\mathrm{2}} }\: \\ $$$$\mathrm{h}_{\mathrm{1}} =\sqrt{{a}^{\mathrm{2}} +\mathrm{5}^{\mathrm{2}} }\:\:\:\:,\:\:\:\mathrm{h}_{\mathrm{2}} =\sqrt{{a}^{\mathrm{2}} +\mathrm{20}^{\mathrm{2}} }\: \\ $$$$\mathrm{H}=\mathrm{h}_{\mathrm{1}} +\mathrm{h}_{\mathrm{2}} \\ $$$$\sqrt{\left({a}+\mathrm{5}\right)^{\mathrm{2}} +\left({a}+\mathrm{20}\right)^{\mathrm{2}} }\:=\sqrt{{a}^{\mathrm{2}} +\mathrm{5}^{\mathrm{2}} }\:+\sqrt{{a}^{\mathrm{2}} +\mathrm{20}^{\mathrm{2}} }\: \\ $$$${a}^{\mathrm{2}} +\mathrm{10}{a}+\mathrm{25}+{a}^{\mathrm{2}} +\mathrm{40}{a}+\mathrm{400} \\ $$$$\:\:\:\:\:\:={a}^{\mathrm{2}} +\mathrm{25}+{a}^{\mathrm{2}} +\mathrm{400}+\mathrm{2}\sqrt{{a}^{\mathrm{2}} +\mathrm{25}}\:\sqrt{{a}^{\mathrm{2}} +\mathrm{400}} \\ $$$$\mathrm{2}\sqrt{{a}^{\mathrm{2}} +\mathrm{25}}\:\sqrt{{a}^{\mathrm{2}} +\mathrm{400}}\:=\mathrm{50}{a} \\ $$$$\:\:\:\left({a}^{\mathrm{2}} +\mathrm{25}\right)\left({a}^{\mathrm{2}} +\mathrm{400}\right)=\mathrm{625}{a}^{\mathrm{2}} \\ $$$$\left({a}^{\mathrm{2}} \right)^{\mathrm{2}} −\mathrm{200}{a}^{\mathrm{2}} +\mathrm{10000}=\mathrm{0} \\ $$$$\left({a}^{\mathrm{2}} −\mathrm{100}\right)^{\mathrm{2}} =\mathrm{0} \\ $$$$\:\:{a}^{\mathrm{2}} =\mathrm{100} \\ $$$$\:\blacksquare=\mathrm{100} \\ $$
Commented by Acem last updated on 26/Oct/22
$${You}'{re}\:{accurate}!\:{thanks} \\ $$
Answered by CElcedricjunior last updated on 26/Oct/22