Question

Номер 129 пожалуйста помогите!!!!

Answer 1

$(1frac{2}{7}x-frac{1}{3})bullet21=2,\\1frac{2}{7}x-frac{1}{3}=frac{2}{21},\\1frac{2}{7}x=frac{2}{21}+frac{1}{3},\\frac{9}{7}x=frac{2}{21}+frac{7}{21},\\frac{9}{7}x=frac{9}{21} |:9,\\frac{x}{7}=frac{1}{21} |bullet 7,\\x=frac{7}{21}=frac{1}{3}.$