1. Вычислите: а) (2/3 + 2/9)(5 1/2 + 1 1/4); б) 2/3 + 2/9(5 1/2 + 1 1/4).

а)

\(\frac{2}{3}+\frac{2}{9}=\frac{6}{9}+\frac{2}{9}=\frac{8}{9}\).

\(5\frac{1}{2}+1\frac{1}{4}=\frac{11}{2}+\frac{5}{4}=\frac{22}{4}+\frac{5}{4}=\frac{27}{4}\).

\(\frac{8}{9}\cdot\frac{27}{4}=6\).

б)

\(5\frac{1}{2}+1\frac{1}{4}=\frac{27}{4}\).

\(\frac{2}{9}\cdot\frac{27}{4}=\frac{3}{2}\).

\(\frac{2}{3}+\frac{3}{2}=\frac{4}{6}+\frac{9}{6}=\frac{13}{6}=2\frac{1}{6}\).

Ответ: а) 6; б) \(2\frac{1}{6}\).