945 Вправа 945Алгебра 8 клас Бевз 2025 · § 18 · стор. 177

945. Обчисли −12 3/80 + (−1/5 + (−1/2) : (−0,8)) : (−2).

1) ${\displaystyle (-\frac{1}{2}):(-0,8)=}$${\displaystyle \frac{1}{2}:\frac{4}{5}=}$${\displaystyle \frac{1}{2}\cdot \frac{5}{4}=}$${\displaystyle \frac{5}{8}}$;

2) ${\displaystyle -\frac{1^{\mathrm{\setminus }8}}{5}+\frac{5^{\mathrm{\setminus }5}}{8}=}$${\displaystyle \frac{-8+25}{40}=}$${\displaystyle \frac{17}{40}}$;

3) ${\displaystyle \frac{17}{40}:(-2)=}$${\displaystyle -\frac{17}{80}}$;

4) ${\displaystyle -12\frac{3}{80}-\frac{17}{80}=}$${\displaystyle -12\frac{20}{80}=}$${\displaystyle -12\frac{1}{4}}$.