143° Вправа 143Алгебра 8 клас Тарасенкова 2025 · § 4 · стор. 46

143. Знайдіть різницю дробів.

1) ${\displaystyle \frac{1}{8ab}-\frac{11}{8ab}=}$${\displaystyle \frac{1-11}{8ab}=}$${\displaystyle \frac{-10}{8ab}=}$${\displaystyle -\frac{\stackrel{5}{\cancel{10}}}{\underset{4}{\cancel{8}}ab}=}$${\displaystyle -\frac{5}{4ab}}$;

2) ${\displaystyle \frac{4y}{5ac}-\frac{4y}{5ac}=}$${\displaystyle \frac{4y-4y}{5ac}=}$${\displaystyle \frac{0}{5ac}=}$${\displaystyle 0}$;

3) ${\displaystyle \frac{12xy}{5a{b}^2}-\frac{3xy}{5a{b}^2}=}$${\displaystyle \frac{12xy-3xy}{5a{b}^2}=}$${\displaystyle \frac{9xy}{5a{b}^2}}$;

4) ${\displaystyle \frac{9a}{a+b}-\frac{4a}{a+b}=}$${\displaystyle \frac{9a-4a}{a+b}=}$${\displaystyle \frac{5a}{a+b}}$;

5) ${\displaystyle \frac{5c}{a+c}-\frac{12c}{a+c}=}$${\displaystyle \frac{5c-12c}{a+c}=}$${\displaystyle -\frac{7c}{a+c}}$;

6) ${\displaystyle \frac{8x}{a^2+3}-\frac{x}{a^2+3}=}$${\displaystyle \frac{8x-x}{a^2+3}=}$${\displaystyle \frac{7x}{a^2+3}}$.