\frac{2}{15} (b+5)- \frac{3}{10} (5b-1)=4
\frac{2}{15} b+ \frac{2}{3} - \frac{3}{2} b+ \frac{3}{10} =4
\frac{4}{30} b- \frac{45}{30} b=4- \frac{9}{30} - \frac{20}{30}
- \frac{41}{30} b=3 \frac{1}{30}
b= \frac{91}{30}* -\frac{30}{41} \\ b= -\frac{91}{41} \\ b=-2 \frac{9}{41}
Объяснение:
