1. Вычислите: a) (-2/3)³ + 2/3 - 2/(-3)³; б) 5² - (-3)² - (-1)°.

1. Вычислите:

a) $$(-2/3)^3 + \frac{2}{3} - \frac{2}{(-3)^3}$$

$$(-2/3)^3 = -\frac{8}{27}$$

$$\frac{2}{(-3)^3} = \frac{2}{-27} = -\frac{2}{27}$$

$$-\frac{8}{27} + \frac{2}{3} - (-\frac{2}{27}) = -\frac{8}{27} + \frac{2}{3} + \frac{2}{27} = \frac{-8 + 18 + 2}{27} = \frac{12}{27} = \frac{4}{9}$$

Ответ: $$\frac{4}{9}$$

б) $$5^2 - (-3)^2 - (-1)^0$$

$$5^2 = 25$$

$$(-3)^2 = 9$$

$$(-1)^0 = 1$$

$$25 - 9 - 1 = 15$$

Ответ: $$15$$