a) $$y = x^6$$, $$x_0 = -2$$
$$y' = 6x^5$$
$$y'(-2) = 6*(-2)^5 = 6*(-32) = -192$$
б) $$y = \frac{-8}{x} = -8x^{-1}$$, $$x_0 = 4$$
$$y' = 8x^{-2} = \frac{8}{x^2}$$
$$y'(4) = \frac{8}{4^2} = \frac{8}{16} = \frac{1}{2}$$
в) $$y = 6 - 3x$$, $$x_0 = 5$$
$$y' = -3$$
$$y'(5) = -3$$
г) $$y = 15\sqrt{x} = 15x^{\frac{1}{2}}$$, $$x_0 = 25$$
$$y' = 15 * \frac{1}{2}x^{-\frac{1}{2}} = \frac{15}{2\sqrt{x}}$$
$$y'(25) = \frac{15}{2\sqrt{25}} = \frac{15}{2*5} = \frac{15}{10} = \frac{3}{2}$$