Решим уравнения:
a) $$25 = 26x - x^2$$
$$x^2 - 26x + 25 = 0$$
$$D = (-26)^2 - 4 \cdot 1 \cdot 25 = 676 - 100 = 576$$
$$x_1 = \frac{26 + \sqrt{576}}{2} = \frac{26 + 24}{2} = \frac{50}{2} = 25$$
$$x_2 = \frac{26 - \sqrt{576}}{2} = \frac{26 - 24}{2} = \frac{2}{2} = 1$$
Ответ: $$x_1 = 25, x_2 = 1$$
б) $$3t^2 = 10 - 29t$$
$$3t^2 + 29t - 10 = 0$$
$$D = (29)^2 - 4 \cdot 3 \cdot (-10) = 841 + 120 = 961$$
$$t_1 = \frac{-29 + \sqrt{961}}{6} = \frac{-29 + 31}{6} = \frac{2}{6} = \frac{1}{3}$$
$$t_2 = \frac{-29 - \sqrt{961}}{6} = \frac{-29 - 31}{6} = \frac{-60}{6} = -10$$
Ответ: $$t_1 = \frac{1}{3}, t_2 = -10$$
в) $$y^2 = 4y + 96$$
$$y^2 - 4y - 96 = 0$$
$$D = (-4)^2 - 4 \cdot 1 \cdot (-96) = 16 + 384 = 400$$
$$y_1 = \frac{4 + \sqrt{400}}{2} = \frac{4 + 20}{2} = \frac{24}{2} = 12$$
$$y_2 = \frac{4 - \sqrt{400}}{2} = \frac{4 - 20}{2} = \frac{-16}{2} = -8$$
Ответ: $$y_1 = 12, y_2 = -8$$
г) $$3p^2 + 3 = 10p$$
$$3p^2 - 10p + 3 = 0$$
$$D = (-10)^2 - 4 \cdot 3 \cdot 3 = 100 - 36 = 64$$
$$p_1 = \frac{10 + \sqrt{64}}{6} = \frac{10 + 8}{6} = \frac{18}{6} = 3$$
$$p_2 = \frac{10 - \sqrt{64}}{6} = \frac{10 - 8}{6} = \frac{2}{6} = \frac{1}{3}$$
Ответ: $$p_1 = 3, p_2 = \frac{1}{3}$$
д) $$x^2 - 20x = 20x + 100$$
$$x^2 - 40x - 100 = 0$$
$$D = (-40)^2 - 4 \cdot 1 \cdot (-100) = 1600 + 400 = 2000$$
$$x_1 = \frac{40 + \sqrt{2000}}{2} = \frac{40 + 20\sqrt{5}}{2} = 20 + 10\sqrt{5}$$
$$x_2 = \frac{40 - \sqrt{2000}}{2} = \frac{40 - 20\sqrt{5}}{2} = 20 - 10\sqrt{5}$$
Ответ: $$x_1 = 20 + 10\sqrt{5}, x_2 = 20 - 10\sqrt{5}$$
е) $$25x^2 - 13x = 10x^2 - 7$$
$$15x^2 - 13x + 7 = 0$$
$$D = (-13)^2 - 4 \cdot 15 \cdot 7 = 169 - 420 = -251$$
D < 0, нет корней
Ответ: нет корней