1018. a) 1 1/5 · 2; б) 2 1/5 · 3; д) 2 · 5 3/4; e) 2 2/5 · 9;

а) $$1 \frac{1}{5} \cdot 2 = \frac{6}{5} \cdot 2 = \frac{6 \cdot 2}{5} = \frac{12}{5} = 2 \frac{2}{5}$$

б) $$2 \frac{1}{5} \cdot 3 = \frac{11}{5} \cdot 3 = \frac{11 \cdot 3}{5} = \frac{33}{5} = 6 \frac{3}{5}$$

д) $$2 \cdot 5 \frac{3}{4} = 2 \cdot \frac{23}{4} = \frac{2 \cdot 23}{4} = \frac{46}{4} = \frac{23}{2} = 11 \frac{1}{2}$$

e) $$2 \frac{2}{5} \cdot 9 = \frac{12}{5} \cdot 9 = \frac{12 \cdot 9}{5} = \frac{108}{5} = 21 \frac{3}{5}$$

Ответ: а) $$2 \frac{2}{5}$$; б) $$6 \frac{3}{5}$$; д) $$11 \frac{1}{2}$$; e) $$21 \frac{3}{5}$$