Блок № 1. Вычислите: №1) 1/10 + 11/18; №2) 2/5 + 4/15; №3) 4/45 + 8/35; №4) 1/42 + 31/39; №5) 23/30 + 1/10; №6) 1 1/15 − 31/33; №7) 4 1/19 − 3 27/38; №8) 2 17/18 − 1 31/38; №9) 5 1/21 − 4 32/35; №10) 1 1/18 − 11/14; №11) 12/35 · 1 3/4 − 4/15; №12) 7 8/21 · 7/65 − 5/42.

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Accepted Answer

\(\frac{1}{10}+\frac{11}{18}=\frac{9}{90}+\frac{55}{90}=\frac{64}{90}=\frac{32}{45}\).
\(\frac{2}{5}+\frac{4}{15}=\frac{6}{15}+\frac{4}{15}=\frac{2}{3}\).
\(\frac{4}{45}+\frac{8}{35}=\frac{28}{315}+\frac{72}{315}=\frac{20}{63}\).
\(\frac{1}{42}+\frac{31}{39}=\frac{13}{546}+\frac{434}{546}=\frac{447}{546}=\frac{149}{182}\).
\(\frac{23}{30}+\frac{1}{10}=\frac{23}{30}+\frac{3}{30}=\frac{13}{15}\).
\(1\frac{1}{15}-\frac{31}{33}=\frac{16}{15}-\frac{31}{33}=\frac{176-155}{165}=\frac{7}{55}\).
\(4\frac{1}{19}-3\frac{27}{38}=\frac{77}{19}-\frac{141}{38}=\frac{154-141}{38}=\frac{13}{38}\).
\(2\frac{17}{18}-1\frac{31}{38}=\frac{53}{18}-\frac{69}{38}=\frac{1007-621}{342}=\frac{193}{171}\).
\(5\frac{1}{21}-4\frac{32}{35}=\frac{106}{21}-\frac{172}{35}=\frac{530-516}{105}=\frac{2}{15}\).
\(1\frac{1}{18}-\frac{11}{14}=\frac{19}{18}-\frac{11}{14}=\frac{133-99}{126}=\frac{17}{63}\).
Сначала выполняем умножение: \(\frac{12}{35}\cdot1\frac{3}{4}-\frac{4}{15}=\frac{12}{35}\cdot\frac{7}{4}-\frac{4}{15}=\frac{3}{5}-\frac{4}{15}=\frac{1}{3}\).
\(7\frac{8}{21}\cdot\frac{7}{65}-\frac{5}{42}=\frac{155}{21}\cdot\frac{7}{65}-\frac{5}{42}=\frac{1}{3}-\frac{5}{42}=\frac{3}{14}\).

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