Приведите дроби к наименьшему общему знаменателю 1) 3/5 5/6 6/11 4/9 2) 5/6 4/11 7/18 1/6...

Найдём НОК чисел :
1.
5 = 5
6 = 2 * 3
9 = 3 * 3
11 = 11
НОК (5; 6; 9; 11) = 11 * 5 * 2 * 3 * 3 = 990 ⇒

$\frac{3}{5}$ = $\frac{3 * 198}{5 * 198}$ = $\frac{594}{990}$
$\frac{5}{6}$ = $\frac{5 * 165}{6 * 165}$ = $\frac{825}{990}$
$\frac{6}{11}$ = $\frac{6 * 90}{11 * 90}$ = $\frac{540}{990}$
$\frac{4}{9}$ = $\frac{4 * 110}{9 * 110}$ = $\frac{440}{990}$

2.
6 = 2 * 3
11 = 11
18 = 2 * 3 * 3
НОК (6; 11; 18) = 2 * 3 * 3 * 11 = 198 ⇒

$\frac{5}{6}$ = $\frac{5 * 33}{6 * 33}$ = $\frac{165}{198}$
$\frac{4}{11}$ = $\frac{4 * 18}{11 * 18}$ = $\frac{72}{198}$
$\frac{7}{18}$ = $\frac{7 * 11}{18 * 11}$ = $\frac{77}{198}$
$\frac{1}{6}$ = $\frac{1 * 33}{6 * 33}$ = $\frac{33}{198}$

3.
13 = 13
5 = 5
7 = 7
4 = 2 * 2
НОК (13; 5; 7; 4) = 13 * 5 * 7 * 2 * 2 = 1820 ⇒

$\frac{9}{13}$ = $\frac{9 * 140}{13 * 140}$ = $\frac{1260}{1820}$
$\frac{4}{5}$ = $\frac{4 * 364}{5 * 364}$ = $\frac{1456}{1820}$
$\frac{5}{7}$ = $\frac{5 * 260}{7 * 260}$ = $\frac{1300}{1820}$
$\frac{3}{4}$ = $\frac{3 * 455}{4 * 455}$ = $\frac{1365}{1820}$