Question

Решите уравнение 2 7/9: (3 3/4у-11 2/3)+1 6/7=2 4/21

Answer 1

$2 frac{7}{9} : (3 frac{3}{4}y - 11 frac{2}{3} ) + 1 frac{6}{7} = 2 frac{4}{21} \ \ 2 frac{7}{9} : (3 frac{3}{4}y - 11 frac{2}{3} ) = 2 frac{4}{21} -1 frac{6}{7} \ \ 2 frac{7}{9} : (3 frac{3}{4}y - 11 frac{2}{3} ) = 2 frac{4}{21} -1 frac{18}{21} \ \ (3 frac{3}{4}y - 11 frac{2}{3} ) = 2 frac{7}{9} : frac{1}{3} \ \ 3 frac{3}{4}y- 11 frac{2}{3} = frac{25}{3} \ \ 3 frac{3}{4}y= 8 frac{1}{3} + 11 frac{2}{3}$
$y= 20 : 3 frac{3}{4}= frac{20}{1} * frac{4}{15} = frac{4*4}{1*3} \ \ y= 5 frac{1}{3}$

проверим:
$2 frac{7}{9} : (3 frac{3}{4}* 5 frac{1}{3} - 11 frac{2}{3} ) + 1 frac{6}{7} = 2 frac{4}{21} \ \ 2 frac{7}{9} : (3 frac{3}{4}* 5 frac{1}{3} - 11 frac{2}{3} ) + 1 frac{6}{7} = 2 frac{4}{21} \ \ 2 frac{7}{9} : (20 - 11 frac{2}{3} ) + 1 frac{6}{7} = 2 frac{4}{21} \ \ 2 frac{7}{9} : 8 frac{1}{3} + 1 frac{6}{7} = 2 frac{4}{21} \ \ frac{25}{9} * frac{3}{25} + 1 frac{6}{7} = 2 frac{4}{21} \ \ frac{1}{3} + 1 frac{6}{7} = 2 frac{4}{21}$
$frac{7}{21} + 1 frac{18}{21} = 2 frac{4}{21} \ \ 2 frac{4}{21}= 2 frac{4}{21}$