944° Вправа 944Алгебра 8 клас Тарасенкова 2025 · § 23 · стор. 282

944. Скільки відсотків становить:

1) ${\displaystyle -\frac{9}{14}\cdot 2\frac{1}{3}+\frac{4}{5}\cdot 3\frac{3}{4}=}$${\displaystyle -\frac{9}{14}\cdot \frac{7}{3}+\frac{4}{5}\cdot \frac{15}{4}=}$${\displaystyle -\frac{\stackrel{3}{\cancel{9}}\cdot \stackrel{1}{\cancel{7}}}{\underset{2}{\cancel{14}}\cdot \underset{1}{\cancel{3}}}+\frac{\cancel{4}\cdot \stackrel{3}{\cancel{15}}}{\underset{1}{\cancel{5}}\cdot \cancel{4}}=}$${\displaystyle -\frac{3}{2}+3=}$${\displaystyle -1,5+3=}$${\displaystyle 1,5}$;

${\displaystyle 17,4+(-8,4):1\frac{5}{7}=}$${\displaystyle 17,4-\frac{84}{10}:\frac{12}{7}=}$${\displaystyle 17,4-\frac{84}{10}\cdot \frac{7}{12}=}$${\displaystyle 17,4-\frac{\stackrel{7}{\cancel{84}}\cdot 7}{10\cdot \underset{1}{\cancel{12}}}=}$${\displaystyle 17,4-\frac{49}{10}=}$${\displaystyle 17,4-4,9=}$${\displaystyle 12,5}$;

${\displaystyle \frac{1,5}{12,5}\cdot 100\mathrm{\%}=}$${\displaystyle 0,12\cdot 100\mathrm{\%}=}$${\displaystyle 12\mathrm{\%}}$;

2) ${\displaystyle 63,45:4,7+9,35-{(-4,5)}^2=}$${\displaystyle 13,5+9,35-20,25=}$${\displaystyle 22,85-20,25=}$${\displaystyle 2,6}$;

${\displaystyle (1\frac{11}{15}-3\frac{2}{5}):(-\frac{5}{6})=}$${\displaystyle (1\frac{11}{15}-3\frac{6}{15}):(-\frac{5}{6})=}$${\displaystyle (1\frac{11}{15}-2\frac{21}{15}):(-\frac{5}{6})=}$${\displaystyle -1\frac{10}{15}:(-\frac{5}{6})=}$${\displaystyle -1\frac{2}{3}:(-\frac{5}{6})=}$${\displaystyle -\frac{5}{3}\cdot (-\frac{6}{5})=}$${\displaystyle \frac{\cancel{5}\cdot \stackrel{2}{\cancel{6}}}{\underset{1}{\cancel{3}}\cdot \cancel{5}}=}$${\displaystyle 2}$;

${\displaystyle \frac{2,6}{2}\cdot 100\mathrm{\%}=}$${\displaystyle 1,3\cdot 100\mathrm{\%}=}$${\displaystyle 130\mathrm{\%}}$.