Помогите плиз срочно

№47
$\frac{70}{112}$ = $\frac{5}{8}$
$\frac{39 * 4 }{8 * 13} = \frac{3}{2}$

№48
$\frac{5}{9} = \frac{20}{36}$
$\frac{56}{105} = \frac{8}{15}$

№49
а) $\frac{2}{9}$ и $\frac{3}{5}$ = $\frac{10}{45}$ и $\frac{27}{45}$
б) $\frac{6}{7}$ и $\frac{9}{14}$ = $\frac{12}{14}$ и $\frac{9}{14}$
в) $\frac{13}{28}$ и $\frac{8}{21}$ = $\frac{39}{84}$ и $\frac{32}{84}$
г) $\frac{1}{504}$ и $\frac{1}{756}$ = $\frac{3}{1512}$ и $\frac{2}{1512}$

№50
а) $\frac{30}{36}$ и $\frac{14}{35}$ = $\frac{5}{6}$ и $\frac{2}{5}$ = $\frac{25}{30}$ и $\frac{12}{30}$
б) $\frac{21}{70}$ и $\frac{28}{105}$ = $\frac{3}{10}$ и $\frac{4}{15}$ = $\frac{9}{30}$ и $\frac{8}{30}$

№51
$\frac{x - 3}{17}$ = $\frac{24}{51}$
$\frac{3(x - 3)}{3 * 17}$ = $\frac{24}{51}$
$\frac{3x - 9}{51}$ = $\frac{24}{51}$
3х - 9 = 24
3х = 24 + 9
3х = 33
х = $\frac{33}{3}$
х = 11