Question

Можно с объяснением плиз

Answer 1

используем формулу

$( {\frac{u}{v})}^{l} = \frac{ {u}^{l} v - {v}^{l}u }{ {v}^{2} }$

${f}^{l} (x) = \frac{ {(3x - 4})^{l}(4 + 2x) - {(4 + 2x)}^{l} (3x - 4) }{ {(4 + 2x)}^{2} } = \\ = \frac{3(4 + 2x) - 2(3x - 4)}{ {(4 + 2x)}^{2} } = \frac{12 + 6x - 6x + 8}{ {(4 + 2x)}^{2} } = \\ = \frac{20}{ {(4 + 2x)}^{2} } \\ {f}^{l} (1) = \frac{20}{ {(4 + 2 \times 1)}^{2} } = \frac{20}{36} = \frac{5}{9}$