Question

10 баллов номер 1091

Answer 1

1091.
1)
 5/6 * 9/15 - 5/12 * 4/15 =
$frac{5}{2*3}* frac{3*3}{3*5} - frac{5}{3*4}* frac{4}{3*5}= frac{1}{2}- frac{1}{9}= frac{7}{18}$
2)
$frac{7}{2*9}* frac{9}{2*7}+ frac{1}{3}* frac{2*3}{7}= frac{1}{4}+ frac{2}{7}= frac{15}{28}$
3)
$frac{3*3*2}{5*4*3}+ frac{5*7}{2*7*5*5}= frac{6}{10}+ frac{1}{10}= frac{7}{10}$
4)
$frac{15*2}{4*5}- frac{81*5}{27*25}= frac{3}{2}- frac{3}{5}= frac{9}{10}$