Объяснение:

[tex]5b(2a - b) - 3(2a - b) = (2a - b)(5b - 3) = (6 \frac{1}{5} - 2.4)(5 \times 6 \frac{1}{5} - 3) = ( \frac{31}{5} - \frac{24}{10} )( \frac{5}{1} \times \frac{31}{5} - 3) = ( \frac{62}{10} - \frac{24}{10} )(31 - 3) = \frac{38}{10} \times 28 = 3.8 \times 28 = 106.4[/tex]