Question Number 189576 by normans last updated on 18/Mar/23
$$ \\ $$$$\:\:\:\:\:\mathrm{2}^{\boldsymbol{{x}}} \:+\:\mathrm{2}^{\boldsymbol{{x}}} −\mathrm{4}\:+\:\boldsymbol{{x}}\:=\:−\frac{\mathrm{1}}{\mathrm{2}}\:\:\:\:\:\:\: \\ $$$$\:\:\:\:\:\:\boldsymbol{{x}}\:=\:??? \\ $$$$ \\ $$
Answered by Gbenga last updated on 18/Mar/23
$$\:\:\:\:\:\:\:\:\:\boldsymbol{\mathrm{solution}} \\ $$$$\mathrm{2}^{\boldsymbol{\mathrm{x}}} +\mathrm{2}^{\boldsymbol{\mathrm{x}}} −\mathrm{4}+\boldsymbol{\mathrm{x}}=−\frac{\mathrm{1}}{\mathrm{2}} \\ $$$$\mathrm{2}\left(\mathrm{2}^{\boldsymbol{\mathrm{x}}} \right)+\boldsymbol{\mathrm{x}}=−\frac{\mathrm{1}}{\mathrm{2}}+\mathrm{4}=\frac{\mathrm{7}}{\mathrm{2}} \\ $$$$\mathrm{2}^{\boldsymbol{\mathrm{x}}+\mathrm{1}} +\boldsymbol{\mathrm{x}}=\frac{\mathrm{7}}{\mathrm{2}} \\ $$$$\mathrm{2}^{\boldsymbol{\mathrm{x}}+\mathrm{1}} =\frac{\mathrm{7}}{\mathrm{2}}−\boldsymbol{\mathrm{x}} \\ $$$$\left(\mathrm{2}^{\boldsymbol{\mathrm{x}}+\mathrm{1}} \right)\mathrm{2}^{−\boldsymbol{\mathrm{x}}} =\left(\frac{\mathrm{7}}{\mathrm{2}}−\boldsymbol{\mathrm{x}}\right)\mathrm{2}^{−\boldsymbol{\mathrm{x}}} \\ $$$$\mathrm{2}=\left(\frac{\mathrm{7}}{\mathrm{2}}−\boldsymbol{\mathrm{x}}\right)\mathrm{2}^{−\boldsymbol{\mathrm{x}}} \\ $$$$\mathrm{2}\left(\mathrm{2}^{\frac{\mathrm{7}}{\mathrm{2}}} \right)=\left(\frac{\mathrm{7}}{\mathrm{2}}−\boldsymbol{\mathrm{x}}\right)\mathrm{2}^{\frac{\mathrm{7}}{\mathrm{2}}−\boldsymbol{\mathrm{x}}} \\ $$$$\mathrm{16}\sqrt{\mathrm{2}}=\left(\frac{\mathrm{7}}{\mathrm{2}}−\boldsymbol{\mathrm{x}}\right)\boldsymbol{\mathrm{e}}^{\left(\frac{\mathrm{7}}{\mathrm{2}}−\boldsymbol{\mathrm{x}}\right)\boldsymbol{\mathrm{ln}}\left(\mathrm{2}\right)} \\ $$$$\mathrm{16}\sqrt{\mathrm{2}}\boldsymbol{\mathrm{ln}}\left(\mathrm{2}\right)=\left(\frac{\mathrm{7}}{\mathrm{2}}−\boldsymbol{\mathrm{x}}\right)\boldsymbol{\mathrm{ln}}\left(\mathrm{2}\right)\boldsymbol{\mathrm{e}}^{\left(\frac{\mathrm{7}}{\mathrm{2}}−\boldsymbol{\mathrm{x}}\right)\boldsymbol{\mathrm{ln}}\left(\mathrm{2}\right)} \\ $$$$\boldsymbol{\mathrm{W}}\left(\mathrm{16}\sqrt{\mathrm{2}}\boldsymbol{\mathrm{ln}}\left(\mathrm{2}\right)\right)=\boldsymbol{\mathrm{W}}\left(\left(\frac{\mathrm{7}}{\mathrm{2}}−\boldsymbol{\mathrm{x}}\right)\boldsymbol{\mathrm{ln}}\left(\mathrm{2}\right)\boldsymbol{\mathrm{e}}^{\left(\frac{\mathrm{7}}{\mathrm{2}}−\boldsymbol{\mathrm{x}}\right)\boldsymbol{\mathrm{ln}}\left(\mathrm{2}\right)} \right) \\ $$$$\left(\frac{\mathrm{7}}{\mathrm{2}}−\boldsymbol{\mathrm{x}}\right)\boldsymbol{\mathrm{ln}}\left(\mathrm{2}\right)=\boldsymbol{\mathrm{W}}\left(\mathrm{16}\sqrt{\mathrm{2}}\boldsymbol{\mathrm{ln}}\left(\mathrm{2}\right)\right) \\ $$$$\left(\frac{\mathrm{7}}{\mathrm{2}}−\boldsymbol{\mathrm{x}}\right)=\frac{\boldsymbol{\mathrm{W}}\left(\mathrm{16}\sqrt{\mathrm{2}}\boldsymbol{\mathrm{ln}}\left(\mathrm{2}\right)\right)}{\boldsymbol{\mathrm{ln}}\left(\mathrm{2}\right)} \\ $$$$\boldsymbol{\mathrm{x}}=\frac{\mathrm{7}}{\mathrm{2}}−\frac{\boldsymbol{\mathrm{W}}\left(\mathrm{16}\sqrt{\mathrm{2}}\boldsymbol{\mathrm{ln}}\left(\mathrm{2}\right)\right)}{\boldsymbol{\mathrm{ln}}\left(\mathrm{2}\right)}\approx\mathrm{0}.\mathrm{5571929518106867}… \\ $$$$\bigstar\boldsymbol{{Small}}\:\boldsymbol{{Laplace}}\bigstar \\ $$