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Question-198050




Question Number 198050 by akolade last updated on 09/Oct/23
Answered by mr W last updated on 10/Oct/23
2^x =3^y =k, say  ⇒x=((log k)/(log 2)), y=((log k)/(log 3))  ((2×log 2+3×log 3)/(log k))=1  log k=log 2^2 ×3^3 =log 108  ⇒k=108  2^x +3^y =2k=216 ✓
$$\mathrm{2}^{{x}} =\mathrm{3}^{{y}} ={k},\:{say} \\ $$$$\Rightarrow{x}=\frac{\mathrm{log}\:{k}}{\mathrm{log}\:\mathrm{2}},\:{y}=\frac{\mathrm{log}\:{k}}{\mathrm{log}\:\mathrm{3}} \\ $$$$\frac{\mathrm{2}×\mathrm{log}\:\mathrm{2}+\mathrm{3}×\mathrm{log}\:\mathrm{3}}{\mathrm{log}\:{k}}=\mathrm{1} \\ $$$$\mathrm{log}\:{k}=\mathrm{log}\:\mathrm{2}^{\mathrm{2}} ×\mathrm{3}^{\mathrm{3}} =\mathrm{log}\:\mathrm{108} \\ $$$$\Rightarrow{k}=\mathrm{108} \\ $$$$\mathrm{2}^{{x}} +\mathrm{3}^{{y}} =\mathrm{2}{k}=\mathrm{216}\:\checkmark \\ $$
Commented by necx122 last updated on 09/Oct/23
My goodness. The approach is really  cool.
$${My}\:{goodness}.\:{The}\:{approach}\:{is}\:{really} \\ $$$${cool}. \\ $$
Commented by akolade last updated on 10/Oct/23
wow this is the best approach i have seen so far
$$\mathrm{wow}\:\mathrm{this}\:\mathrm{is}\:\mathrm{the}\:\mathrm{best}\:\mathrm{approach}\:\mathrm{i}\:\mathrm{have}\:\mathrm{seen}\:\mathrm{so}\:\mathrm{far} \\ $$

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