№1 Найти значение выражения: 1) $$17^2$$; 2) $$(-4)^3$$; 3) $$(-\frac{1}{9})^2$$ 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) $$(-4)^3 = -4 \times -4 \times -4 = -64$$

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

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

5) -2,8 × (-$$1\frac{1}{7}$$) = -2,8 × (-$$\frac{8}{7}$$) = -$$\frac{28}{10}$$ × (-$$\frac{8}{7}$$) = $$\frac{4}{1}$$ × $$\frac{4}{5}$$ = $$\frac{16}{5}$$ = 3,2

5) -4$$\frac{2}{7}$$ : 1$$\frac{19}{21}$$ = -$$\frac{30}{7}$$ : $$\frac{40}{21}$$ = -$$\frac{30}{7}$$ × $$\frac{21}{40}$$ = -$$\frac{3}{1}$$ × $$\frac{3}{4}$$ = -$$\frac{9}{4}$$ = -2$$\frac{1}{4}$$ = -2,25