145° Вправа 145Алгебра 8 клас Тарасенкова 2025 · § 4 · стор. 46

145. Знайдіть різницю a/(9c) − b/(9c), якщо:

${\displaystyle \frac{a}{9c}-\frac{b}{9c}=}$${\displaystyle \frac{a-b}{9c}}$.

1) ${\displaystyle \frac{5c^2-4c^2}{9c}=}$${\displaystyle \frac{c^2}{9c}=}$${\displaystyle \frac{\cancel{c}\cdot c}{9\cancel{c}}=}$${\displaystyle \frac{c}{9}}$;

2) ${\displaystyle \frac{7c-(-10c)}{9c}=}$${\displaystyle \frac{17c}{9c}=}$${\displaystyle \frac{17\cancel{c}}{9\cancel{c}}=}$${\displaystyle \frac{17}{9}=}$${\displaystyle 1\frac{8}{9}}$;

3) ${\displaystyle \frac{15a{c}^2-6a{c}^2}{9c}=}$${\displaystyle \frac{9a{c}^2}{9c}=}$${\displaystyle \frac{\cancel{9c}\cdot ac}{\cancel{9c}}=}$${\displaystyle ac}$.