Question

$frac{3}{4x} - frac{2}{5x}$ при x=0.7 

Answer 1

$frac{3}{4x} - frac{2}{5x} = frac{15-8}{20x} = frac{7}{20x}$
Еслих=0,7, то $frac{7}{20x}= frac{7}{20cdot0.7} = frac{7}{14} = frac{1}{2}$

Ответ: 1/2