Дискриминант: $$D = (-7)^2 - 4 \cdot 3 \cdot 4 = 49 - 48 = 1$$
Корни: $$x_1 = \frac{7 + \sqrt{1}}{2 \cdot 3} = \frac{8}{6} = \frac{4}{3}$$, $$x_2 = \frac{7 - \sqrt{1}}{2 \cdot 3} = \frac{6}{6} = 1$$
Дискриминант: $$D = (-8)^2 - 4 \cdot 5 \cdot 3 = 64 - 60 = 4$$
Корни: $$x_1 = \frac{8 + \sqrt{4}}{2 \cdot 5} = \frac{10}{10} = 1$$, $$x_2 = \frac{8 - \sqrt{4}}{2 \cdot 5} = \frac{6}{10} = \frac{3}{5}$$
Дискриминант: $$D = (-13)^2 - 4 \cdot 3 \cdot 14 = 169 - 168 = 1$$
Корни: $$x_1 = \frac{13 + \sqrt{1}}{2 \cdot 3} = \frac{14}{6} = \frac{7}{3}$$, $$x_2 = \frac{13 - \sqrt{1}}{2 \cdot 3} = \frac{12}{6} = 2$$
Дискриминант: $$D = (-9)^2 - 4 \cdot 2 \cdot 10 = 81 - 80 = 1$$
Корни: $$y_1 = \frac{9 + \sqrt{1}}{2 \cdot 2} = \frac{10}{4} = \frac{5}{2}$$, $$y_2 = \frac{9 - \sqrt{1}}{2 \cdot 2} = \frac{8}{4} = 2$$
Дискриминант: $$D = (-6)^2 - 4 \cdot 5 \cdot 1 = 36 - 20 = 16$$
Корни: $$y_1 = \frac{6 + \sqrt{16}}{2 \cdot 5} = \frac{10}{10} = 1$$, $$y_2 = \frac{6 - \sqrt{16}}{2 \cdot 5} = \frac{2}{10} = \frac{1}{5}$$
Дискриминант: $$D = 1^2 - 4 \cdot 4 \cdot (-33) = 1 + 528 = 529$$
Корни: $$x_1 = \frac{-1 + \sqrt{529}}{2 \cdot 4} = \frac{-1 + 23}{8} = \frac{22}{8} = \frac{11}{4}$$, $$x_2 = \frac{-1 - \sqrt{529}}{2 \cdot 4} = \frac{-1 - 23}{8} = \frac{-24}{8} = -3$$
Дискриминант: $$D = (-10)^2 - 4 \cdot 1 \cdot (-24) = 100 + 96 = 196$$
Корни: $$y_1 = \frac{10 + \sqrt{196}}{2 \cdot 1} = \frac{10 + 14}{2} = \frac{24}{2} = 12$$, $$y_2 = \frac{10 - \sqrt{196}}{2 \cdot 1} = \frac{10 - 14}{2} = \frac{-4}{2} = -2$$
Дискриминант: $$D = 1^2 - 4 \cdot 1 \cdot (-90) = 1 + 360 = 361$$
Корни: $$p_1 = \frac{-1 + \sqrt{361}}{2 \cdot 1} = \frac{-1 + 19}{2} = \frac{18}{2} = 9$$, $$p_2 = \frac{-1 - \sqrt{361}}{2 \cdot 1} = \frac{-1 - 19}{2} = \frac{-20}{2} = -10$$
Ответ: a) x₁ = 4/3, x₂ = 1; б) x₁ = 1, x₂ = 3/5; в) x₁ = 7/3, x₂ = 2; г) y₁ = 5/2, y₂ = 2; д) y₁ = 1, y₂ = 1/5; e) x₁ = 11/4, x₂ = -3; ж) y₁ = 12, y₂ = -2; з) p₁ = 9, p₂ = -10