#146(а,б)..).).).).).).)

Решите задачу:

$1) \frac{4}{15} :x= \frac{2}{5} \\ x= \frac{4}{15} : \frac{2}{5} \\ \frac{4}{15} : \frac{2}{5} = \frac{4*5}{15*2} = \frac{2}{3} \\ \\$

$2) \frac{2}{15} y+ \frac{3}{4} = \frac{5}{6} \\ \frac{2}{15} y= \frac{5}{6} - \frac{3}{4} \\ \frac{5}{6} - \frac{3}{4} = \frac{5*2}{6*2} - \frac{3*3}{4*3} = \frac{10}{12} - \frac{9}{12} = \frac{1}{12} \\ \frac{2}{15} y= \frac{1}{12} \\ y= \frac{1}{12} : \frac{2}{15} \\ \frac{1}{12} : \frac{2}{15} = \frac{1*15}{12*2} = \frac{5}{4*2} = \frac{5}{8} = \frac{5*125}{8*125} = \frac{625}{1000} =0.625$