Question

Пожалуйста даю 80 баллов

Answer 1

Пошаговое объяснение:

№62

1) $\frac{2}{3}a*\frac{7}{12}b=\frac{2*7}{3*12}ab=\frac{2*7}{3*2*6}ab=\frac{7}{3*6}ab=\frac{7}{18}ab$

2) $\frac{8}{9}x*1\frac{4}{5}y=\frac{8}{9}x*\frac{1*5+4}{5}y=\frac{8}{9}x*\frac{9}{5}y=\frac{8*9}{9*5}xy=\frac{8}{5}xy=\frac{8*2}{5*2}xy=\frac{16}{10}xy=1,6xy$

3) $5m*2\frac{6}{11}n*2\frac{5}{14}k=5m*\frac{2*11+6}{11}n*\frac{2*14+5}{14}k=5m*\frac{28}{11}n*\frac{33}{14}k=\frac{5*28*33}{11*14}kmn=\frac{5*2*14*3*11}{11*14}kmn=5*2*3*kmn=30kmn$

№63

1) $\frac{5}{14}x-\frac{9}{28}x+\frac{11}{42}x=(\frac{5}{14}-\frac{9}{14*2}+\frac{11}{14*3})*x=(\frac{5*3*2}{14*3*2}-\frac{9*3}{14*2*3}+\frac{11*2}{14*3*2})*x=\frac{30-27+22}{14*3*2}*x=\frac{25}{84}x$

2) $8\frac{13}{18}m-4\frac{7}{12}m+5\frac{5}{6}m=(\frac{8*18+13}{18}-\frac{4*12+7}{12}+\frac{5*6+5}{6})m=(\frac{157}{18}-\frac{55}{12}+\frac{35}{6})m=(\frac{157}{3*3*2}-\frac{55}{3*2*2}+\frac{35}{3*2})m=(\frac{157*2}{3*3*2*2}-\frac{55*3}{3*2*2*3}+\frac{35*3*2}{3*2*3*2})m=(\frac{314}{3*3*2*2}-\frac{165}{3*2*2*3}+\frac{210}{3*2*3*2})m=(\frac{314-165+210}{36})m=\frac{359}{36}m=9\frac{35}{36}m$

№65

2) $1\frac{1}{22}*3\frac{2}{3}-(2\frac{5}{6}+3\frac{5}{6}*\frac{7}{23})*\frac{3}{5}=\frac{1*22+1}{22}*\frac{3*3+2}{3}-(\frac{2*6+5}{6}+\frac{3*6+5}{6}*\frac{7}{23})*\frac{3}{5}=\frac{23}{22}*\frac{11}{3}-(\frac{17}{6}+\frac{23}{6}*\frac{7}{23})*\frac{3}{5}=\frac{23*11}{2*11*3}-(\frac{17}{6}+\frac{23*7}{6*23})*\frac{3}{5}=\frac{23}{2*3}-(\frac{17}{6}+\frac{7}{6})*\frac{3}{5}=\frac{23}{6}-\frac{17+7}{6}*\frac{3}{5}=\frac{23}{6}-\frac{24}{6}*\frac{3}{5}=\frac{23*5}{6*5}-\frac{24*3}{6*5}=\frac{23*5-24*3}{6*5}=$

$=\frac{115-72}{30}=\frac{43}{30}=1\frac{13}{30}$

№66

1) $3\frac{3}{7}*2\frac{2}{13}+2\frac{1}{7}*2\frac{2}{13}=2\frac{2}{13}*(3\frac{3}{7}+2\frac{1}{7})=2\frac{2}{13}*5\frac{4}{7}=\frac{2*13+2}{13}*\frac{5*7+4}{7}=\frac{28}{13}*\frac{39}{7}=\frac{28*39}{13*7}=\frac{7*4*13*3}{13*7}=4*3=12$

2) $2\frac{2}{9}*7\frac{1}{5}+\frac{11}{12}*7\frac{1}{5}-7\frac{1}{5}*1\frac{3}{4}=7\frac{1}{5}*(2\frac{2}{9}+\frac{11}{12}-1\frac{3}{4})=\frac{7*5+1}{5}*(\frac{2*9+2}{9}+\frac{11}{12}-\frac{1*4+3}{4})=\frac{36}{5}*(\frac{20}{9}+\frac{11}{12}-\frac{7}{4})=\frac{36}{5}*(\frac{20}{3*3}+\frac{11}{3*4}-\frac{7}{4})=\frac{36}{5}*(\frac{20*4}{3*3*4}+\frac{11*3}{3*4*3}-\frac{7*3*3}{4*3*3})=\frac{36}{5}*(\frac{80+33-63}{4*3*3})=\frac{36}{5}*\frac{50}{36}=\frac{36*50}{5*36}=\frac{36*5*10}{5*36}=10$