Question

Найти значение и проверить пропорцию:
1) x:30=7:10
2)12:x=4:5
3)8:1=24:x
4)45:51=x:34

Answer 1

$\frac{x}{30} = \frac{7}{10} \\ x = \frac{30 \times 7}{10} = 21 \\ \frac{12}{x} = \frac{4}{5} \\ x = \frac{12 \times 5}{4} = 15 \\ \frac{8}{1} = \frac{24}{x} \\ x = \frac{24 \times 1}{8} = 3 \\ \frac{45}{51} = \frac{x}{34} \\ x = \frac{45 \times 34}{51} = 30$