Question

сделайте пж мне надо быстро Я не могу это сделать

Answer 1

Решение.

Сначала преобразуем все смешанные числа в неправильные дроби .

$\displaystyle \bf 1)\ \ \frac{5}{9}+1\frac{5}{7}\cdot \Big(4\frac{2}{3}-2\frac{5}{8}\Big):1\frac{3}{4}=\frac{5}{9}+\frac{12}{7}\cdot \Big(\frac{14}{3}-\frac{21}{8}\Big)\cdot \frac{4}{7}=\\\\\\=\frac{5}{9}+\frac{12}{7}\cdot \frac{49}{24}\cdot \frac{4}{7}=\frac{5}{9}+\frac{7}{2}\cdot \frac{4}{7}=\frac{5}{9}+2=2\frac{5}{9}$

$\displaystyle \bf 2)\ \ 2-3\frac{1}{7}\cdot \Big(2-1\frac{9}{11}\Big):\frac{8}{21}=2-\frac{22}{7}\cdot \Big(2-\frac{20}{11}\Big)\cdot \frac{21}{8}=\\\\\\=2-\frac{22}{7}\cdot \frac{2}{11}\cdot \frac{21}{8}=2-\frac{2\cdot 2\cdot 3}{8}=2-\frac{3}{2}=\frac{1}{2}$

Answer 2

Ответ:

1) $2\frac{5}{9}$; 2) 0,5.

Пошаговое объяснение:

 $\frac{5}{9} +1\frac{5}{7} *(4\frac{2}{3} -2\frac{5}{8})/1\frac{3}{4} =\\ \\ =\frac{5}{9} +\frac{1*7+5}{7} *(\frac{4*3+2}{3} -\frac{2*8+5}{8})/\frac{1*4+3}{4}=\\ \\ =\frac{5}{9} +\frac{12}{7} *(\frac{14}{3} -\frac{21}{8})/\frac{7}{4}=\\ \\= \frac{5}{9} +\frac{12}{7} *(\frac{14*8}{3*8} -\frac{21*3}{8*3})/\frac{7}{4}=\\ \\ =\frac{5}{9} +\frac{12}{7} *(\frac{112}{24} -\frac{63}{24})/\frac{7}{4}=\\ \\ =\frac{5}{9} +\frac{12}{7} *(\frac{112-63}{24})/\frac{7}{4}=$

 $=\frac{5}{9} +\frac{12}{7} *(\frac{112-63}{24})/\frac{7}{4}=\\ \\ =\frac{5}{9} +\frac{12}{7} *\frac{49}{24}/\frac{7}{4} =\\ \\ =\frac{5}{9} +\frac{12}{7} *\frac{49}{24}*\frac{4}{7}=\\ \\ =\frac{5}{9} +\frac{12}{1} *\frac{7}{24}*\frac{4}{7}=\\ \\ =\frac{5}{9} +\frac{7}{2}*\frac{4}{7}=\\ \\ =\frac{5}{9} +\frac{7*4}{2*7}=\frac{5}{9} +\frac{28}{14} =\frac{5}{9} +\frac{4}{2} =\\ \\ =\frac{5}{9} +\frac{2}{1} =2\frac{5}{9}$

______________________________

$2-3\frac{1}{7} *(2-1\frac{9}{11} )/\frac{8}{21} =\\ \\ =2-\frac{3*7+1}{7} *(2-\frac{1*11+9}{11} )/\frac{8}{21} =\\ \\ =2-\frac{22}{7} *(2-\frac{20}{11} )/\frac{8}{21} =\\ \\ =2-\frac{22}{7} *(2-\frac{20}{11} )*\frac{21}{8}=\\ \\ =2-\frac{22}{7} *(\frac{2}{1} -\frac{20}{11} )*\frac{21}{8}=\\ \\ = 2-\frac{22}{7} *(\frac{2*11}{1*11} -\frac{20}{11} )*\frac{21}{8}=\\ \\ =2-\frac{22}{7} *(\frac{22}{11} -\frac{20}{11} )*\frac{21}{8}=\\ \\ =2-\frac{22}{7} *(\frac{22-20}{11})*\frac{21}{8}=$

$=2-\frac{22}{7} *(\frac{22-20}{11})*\frac{21}{8}=\\ \\ =2-\frac{22}{7} *\frac{2}{11}*\frac{21}{8}=\\ \\ =2-\frac{22}{1} *\frac{2}{11} *\frac{3}{8}=\\ \\ = 2-\frac{2}{1} *\frac{2}{1} *\frac{3}{8} =\\ \\ =2-\frac{2}{1} *\frac{3}{4}=2-\frac{3}{2} =\\ \\ =\frac{2}{1} -\frac{3}{2} = \frac{2*2}{1*2} -\frac{3}{2} =\frac{4}{2} -\frac{3}{2} =\frac{1}{2} =0,5$