148. Счёт-тест. Тест 1 (3 мин): 3 5/6 − 2 8/15; 3 7/15 + 2/3; 7 − 3 4/9; 5 1/8 − 4 3/5. Тест 2 (4 мин): 3/14 · 21; 12/7 : 4; 10/27 · 9/25; 5 1/4 : 7/18; 2 5/6 · 12; 6 2/5 : 2; 1 7/9 · 3 3/4; 3/8 · 2 2/3 : 11/15 · 2 1/5.

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Фото задания

148. Счёт-тест. Тест 1 (3 мин): 3 5/6 − 2 8/15; 3 7/15 + 2/3; 7 − 3 4/9; 5 1/8 − 4 3/5. Тест 2 (4 мин): 3/14 · 21; 12/7 : 4; 10/27 · 9/25; 5 1/4 : 7/18; 2 5/6 · 12; 6 2/5 : 2; 1 7/9 · 3 3/4; 3/8 · 2 2/3 : 11/15 · 2 1/5.

Accepted Answer

Тест 1

\(3\frac{5}{6}-2\frac{8}{15}=\frac{23}{6}-\frac{38}{15}=\frac{115-76}{30}=\frac{39}{30}=1\frac{3}{10}\).
\(3\frac{7}{15}+\frac{2}{3}=\frac{52}{15}+\frac{10}{15}=\frac{62}{15}=4\frac{2}{15}\).
\(7-3\frac{4}{9}=\frac{63}{9}-\frac{31}{9}=\frac{32}{9}=3\frac{5}{9}\).
\(5\frac{1}{8}-4\frac{3}{5}=\frac{41}{8}-\frac{23}{5}=\frac{205-184}{40}=\frac{21}{40}\).

Тест 2

\(\frac{3}{14}\cdot21=\frac{9}{2}=4\frac{1}{2}\).
\(\frac{12}{7}:4=\frac{12}{7}\cdot\frac14=\frac37\).
\(\frac{10}{27}\cdot\frac{9}{25}=\frac{2}{15}\).
\(5\frac14:\frac7{18}=\frac{21}{4}\cdot\frac{18}{7}=\frac{27}{2}=13\frac12\).
\(2\frac56\cdot12=\frac{17}{6}\cdot12=34\).
\(6\frac25:2=\frac{32}{5}:2=\frac{16}{5}=3\frac15\).
\(1\frac79\cdot3\frac34=\frac{16}{9}\cdot\frac{15}{4}=\frac{20}{3}=6\frac23\).
\(\frac38\cdot2\frac23:\frac{11}{15}\cdot2\frac15=\frac38\cdot\frac83:\frac{11}{15}\cdot\frac{11}{5}=1:\frac{11}{15}\cdot\frac{11}{5}=3\).

Ответ: Тест 1: \(1\frac{3}{10};\ 4\frac{2}{15};\ 3\frac{5}{9};\ \frac{21}{40}\). Тест 2: \(4\frac12;\ \frac37;\ \frac{2}{15};\ 13\frac12;\ 34;\ 3\frac15;\ 6\frac23;\ 3\).