Răspuns:
[tex]E(x) = ( \frac{2x}{3x - 1} + 1) \div \frac{(5x + 1)(5x - 1)}{ {(3x - 1)}^{2} } \\ E(x) = ( \frac{2x + 3x - 1}{3x - 1} ) \times \frac{ {(3x - 1)}^{2} }{(5x + 1)(5x - 1)} \\ E(x) = \frac{5x - 1}{3x - 1} \times \frac{ {(3x - 1)}^{2} }{(5x + 1)(5x - 1) } \\ E(x) = \frac{3x - 1}{5x + 1} [/tex]
