a) \(2x = \sqrt {13} \)
\( \displaystyle \Leftrightarrow \dfrac{2x}{2} = {{\sqrt {13} } \over 2} \)
\( \displaystyle \Leftrightarrow x = {{\sqrt {13} } \over 2} \Leftrightarrow x \approx 1,803\)
b) \( - 5x = 1 + \sqrt 5 \)
\( \displaystyle\Leftrightarrow \dfrac{-5x}{-5} = - {{1 + \sqrt 5 } \over 5}\)
\( \displaystyle\Leftrightarrow x = - {{1 + \sqrt 5 } \over 5} \Leftrightarrow x \approx - 0,647\)
c) \(x\sqrt 2 = 4\sqrt 3 \)
\( \displaystyle\Leftrightarrow \dfrac{x\sqrt 2}{\sqrt 2} = {{4\sqrt 3 } \over {\sqrt 2 }}\)
\( \displaystyle\Leftrightarrow x = {{4\sqrt 3 } \over {\sqrt 2 }} \Leftrightarrow x \approx 4,899\)
