№1 Найти значение выражения: 1) $$17^2$$; 2) $$(-4)^3$$; 3) $$(-1\frac{1}{9})^2$$ 4) – 7,62 – (-7,62) 5)-2,8×(-1\frac{1}{7})$$ 5)-$$4\frac{2}{7}:1\frac{19}{21}$$

1) $$17^2 = 17 \times 17 = 289$$

2) $$(-4)^3 = (-4) \times (-4) \times (-4) = 16 \times (-4) = -64$$

3) $$(-1\frac{1}{9})^2 = (-\frac{10}{9})^2 = (-\frac{10}{9}) \times (-\frac{10}{9}) = \frac{100}{81} = 1\frac{19}{81}$$

4) – 7,62 – (-7,62) = -7,62 + 7,62 = 0

5) $$-2,8 \times (-1\frac{1}{7}) = -2,8 \times (-\frac{8}{7}) = -\frac{28}{10} \times (-\frac{8}{7}) = \frac{28 \times 8}{10 \times 7} = \frac{4 \times 8}{10} = \frac{32}{10} = 3,2$$

6) $$4\frac{2}{7}:1\frac{19}{21} = \frac{30}{7}:\frac{40}{21} = \frac{30}{7} \times \frac{21}{40} = \frac{30 \times 21}{7 \times 40} = \frac{3 \times 3}{4} = \frac{9}{4} = 2\frac{1}{4}$$