Розвяжіть 1.34, застосовуючи спосіб групування. весь розвязок напишіть будь ласка

Решите задачу:

$[74.7* \frac{2}{21}+(-105.3)*2 \frac{3}{7}-(-105.3)* \frac{2}{21} -2 \frac{3}{7}*74.7 ]:10=$
$=[74.7* \frac{2}{21}-2 \frac{3}{7}*74.7 +(-105.3)*2 \frac{3}{7}-(-105.3)* \frac{2}{21} ]:10=$
$=[74.7* (\frac{2}{21}-2 \frac{3}{7}) +(-105.3)*(2 \frac{3}{7}- \frac{2}{21} )]:10=$
$=[74.7* (\frac{2}{21}-2 \frac{3}{7}) +105.3*(-1)*(2 \frac{3}{7}- \frac{2}{21} )]:10=$
$=[74.7* (\frac{2}{21}-2 \frac{3}{7}) +105.3*( \frac{2}{21} -2 \frac{3}{7} )]:10=$
$=[(74.7+105.3) (\frac{2}{21}-2 \frac{3}{7})]:10 =[180*(\frac{2}{21}-2 \frac{3}{7})]:10=$
$= \frac{10*18*(\frac{2}{21}-2 \frac{3}{7})}{10*1} = \frac{18*(\frac{2}{21}-2 \frac{3}{7})}{1} =18*(\frac{2}{21}-2 \frac{3}{7})=$
$=18*(\frac{2}{21}-\frac{2*7+3}{7})=18*(\frac{2}{21}-\frac{17}{7})= 18*(\frac{2}{21}-\frac{17*3}{7*3})=$
$=18*(\frac{2}{21}-\frac{51}{21})=18* \frac{2-51}{21} =18* \frac{-49}{21}=- \frac{18*49}{21}=- \frac{3*6*7*7}{3*7*1}=$
$=- \frac{6*7}{1} =-6*7=-42$