Question

35пунктов! нужно 9(целых)3/7*5/22 6 3/8* 16/17 2 1/3 *1 1/5 19 1/2*1 5/9 2 1/4*2 2/27 2 8/11*5 2/15 7/9*1 1/14*5 2/5 2 2/3*1 1/24*5 2/5 ! ! и разъясните почему получилось, там 1/7 (к примеру) и т.д !

Answer 1

$9\frac{3}{7}\cdot\frac{5}{22}=\frac{9\cdot7+3}{7}\cdot\frac{5}{22}=\frac{66}{7}\cdot\frac{5}{22}=\frac{66\cdot5}{7\cdot22}=\frac{3\cdot5}{7\cdot1}=\frac{15}{7}=2\frac{1}{7} ;$

$6\frac{3}{8}\cdot\frac{16}{17}=\frac{6\cdot8+3}{8}\cdot\frac{16}{17}=\frac{51}{8}\cdot\frac{16}{17}=\frac{51\cdot16}{8\cdot17}=\frac{3\cdot2}{1\cdot1}=\frac{6}{1}=6;$

$2\frac{1}{3}\cdot1\frac{1}{5}=\frac{2\cdot3+1}{3}\cdot\frac{1\cdot5+1}{5}=\frac{7}{3}\cdot\frac{6}{5}=\frac{7\cdot6}{3\cdot5}=\frac{7\cdot2}{1\cdot5}=\frac{14}{5}=2\frac{4}{5};$

$19\frac{1}{2}\cdot1\frac{5}{9}=\frac{19\cdot2+1}{2}\cdot\frac{1\cdot9+5}{9}=\frac{39}{2}\cdot\frac{14}{9}=\frac{39\cdot14}{2\cdot9}=\frac{13\cdot7}{1\cdot3}=\frac{91}{3}=30\frac{1}{3};$

$2\frac{1}{4}\cdot2\frac{2}{27}=\frac{9}{4}\cdot\frac{56}{27}=\frac{1\cdot14}{1\cdot3}=\frac{14}{3}=4\frac{2}{3};$

$2\frac{8}{11}\cdot5\frac{2}{15}=\frac{30}{11}\cdot\frac{77}{15}=\frac{2\cdot7}{1\cdot1}=14;$

$\frac{7}{9}\cdot1\frac{1}{14}\cdot5\frac{2}{5}=\frac{7}{9}\cdot\frac{15}{14}\cdot\frac{27}{5}=\frac{7\cdot15\cdot27}{9\cdot14\cdot5}=\frac{1\cdot3\cdot3}{1\cdot2\cdot1}=\frac{9}{2}=4\frac{1}{2};$

$2\frac{2}{3}\cdot1\frac{1}{24}\cdot5\frac{2}{5}=\frac{8}{3}\cdot\frac{25}{24}\cdot\frac{27}{5}=\frac{1\cdot5\cdot9}{1\cdot3\cdot1}=\frac{1\cdot5\cdot3}{1\cdot1\cdot1}=15.$