Вариант 1 • 1. Вычислите: a) 6$$\frac{1}{9}$$-4; 6) √7,2-√20;

a) $$6\frac{1}{9}-4 = \frac{6 \cdot 9 + 1}{9} - 4 = \frac{55}{9} - \frac{36}{9} = \frac{55-36}{9} = \frac{19}{9} = 2\frac{1}{9}$$

б)$$\sqrt{7,2} \cdot \sqrt{20} = \sqrt{7,2 \cdot 20} = \sqrt{144} = 12$$

Ответ: a) $$2\frac{1}{9}$$; б) $$12$$