Упр.973 ГДЗ Зубарева Мордкович 6 класс ФГОС (Математика)

а) (5/18+1/12)•6-2 5/7;
б) (5/14-11/21)•2+3;
в) 5/6-(7/15-17/20) :1 1/45;
г)-5/9-1 43/72 :(7/24+3/16).

а) $$\left(\frac{5}{18}+\frac{1}{12}\right)\cdot 6-2\frac{5}{7}$$

$$\frac{5}{18}+\frac{1}{12}=\frac{10}{36}+\frac{3}{36}=\frac{13}{36}$$

$$\frac{13}{36}\cdot 6=\frac{13}{6}$$

$$2\frac{5}{7}=\frac{19}{7}$$

$$\frac{13}{6}-\frac{19}{7}=\frac{91-114}{42}=-\frac{23}{42}$$

б) $$\left(\frac{5}{14}-\frac{11}{21}\right)\cdot 2+3$$

$$\frac{5}{14}-\frac{11}{21}=\frac{15}{42}-\frac{22}{42}=-\frac{7}{42}=-\frac{1}{6}$$

$$-\frac{1}{6}\cdot 2+3=-\frac{1}{3}+3=2\frac{2}{3}$$

в) $$\frac{5}{6}-\left(\frac{7}{15}-\frac{17}{20}\right):1\frac{1}{45}$$

$$\frac{7}{15}-\frac{17}{20}=\frac{28}{60}-\frac{51}{60}=-\frac{23}{60}$$

$$1\frac{1}{45}=\frac{46}{45}$$

$$-\frac{23}{60}:\frac{46}{45}=-\frac{23}{60}\cdot\frac{45}{46}=-\frac{3}{8}$$

$$\frac{5}{6}-\left(-\frac{3}{8}\right)=\frac{5}{6}+\frac{3}{8}=\frac{20}{24}+\frac{9}{24}=\frac{29}{24}=1\frac{5}{24}$$

г) $$-\frac{5}{9}-1\frac{43}{72}:\left(\frac{7}{24}+\frac{3}{16}\right)$$

$$1\frac{43}{72}=\frac{115}{72}$$

$$\frac{7}{24}+\frac{3}{16}=\frac{14}{48}+\frac{9}{48}=\frac{23}{48}$$

$$\frac{115}{72}:\frac{23}{48}=\frac{115}{72}\cdot\frac{48}{23}=\frac{5}{9}\cdot\frac{6}{1}=\frac{10}{3}$$

$$-\frac{5}{9}-\frac{10}{3}=-\frac{5}{9}-\frac{30}{9}=-\frac{35}{9}=-3\frac{8}{9}$$

Ответ

а) $$-\frac{23}{42}$$; б) $$2\frac{2}{3}$$; в) $$1\frac{5}{24}$$; г) $$-3\frac{8}{9}$$.