Решите уравнение:
1) 6 : x = 36 : 30;
2) 12 : 7 = 3 : x;
3) 4,9 : 0,35 = x : 35;
4) $\frac{x}{21} = \frac{9}{14}$;
5) $\frac{x}{16} = \frac{3}{8}$;
6) $\frac{108}{90} = \frac{42}{b}$.
6 : x = 36 : 30
36x = 6 * 30
$x = \frac{6 * 30}{36}$
$x = \frac{1 * 5}{1}$
x = 5
12 : 7 = 3 : x
12x = 7 * 3
$x = \frac{7 * 3}{12}$
$x = \frac{7 * 1}{4}$
$x = \frac{7}{4} = 1\frac{3}{4}$
4,9 : 0,35 = x : 35
0,35x = 4,9 * 35
$x = \frac{4,9 * 35}{0,35}$
$x = \frac{4,9 * 100}{1}$
x = 490
$\frac{x}{21} = \frac{9}{14}$
14x = 21 * 9
$x = \frac{21 * 9}{14}$
$x = \frac{3 * 9}{2}$
$x = \frac{27}{2} = 13\frac{1}{2}$
$\frac{x}{16} = \frac{3}{8}$
8x = 16 * 3
$x = \frac{16 * 3}{8}$
$x = \frac{2 * 3}{1}$
x = 6
$\frac{108}{90} = \frac{42}{b}$
108b = 90 * 42
$b = \frac{90 * 42}{108}$
$b = \frac{5 * 7}{1}$
b = 35
Пожауйста, оцените решение