Question

Решите пропорции

1) x/8=3/4
2) 15:7=75:y
3) 7 1/2:4 4/5=x:8/25
4)3/7=6/2x-3

Answer 1

Ответ:

$\frac{x}{8} = \frac{3}{4} \\ 4x = 24 \\ x = 24 \div 4 \\ x = 6$

$\frac{15}{7} = \frac{75}{y} \\ 15y = 75 \times 7 \\ y = \frac{75 \times 7}{15} = 5 \times 7 = 35 \\ y = 35$

$7 \frac{1}{2} \div 4 \frac{4}{5} =x \div \frac{8}{25} \\ \frac{15}{2} \div \frac{24}{5} = \frac{25}{8} x \\ \frac{25}{8} x = \frac{15}{2} \times \frac{5}{24} = \frac{75}{48} \\ x = \frac{75}{48} \div \frac{25}{8} = \frac{75}{48} \times \frac{8}{25} = \frac{3}{6} = \frac{1}{2} \\ x = \frac{1}{2}$