Question

Решите уравнение.
А) 6х-5=4/х
Б)х4-4х2-45=0
Помогите пожалуйста ребята

Answer 1

А)
$6x - 5 = \frac{4}{x} \\ (6x - 5)x = 4 \\ (6x - 5)x - 4 = 0 \\ 6 {x}^{2} - 5x - 4 = 0 \\ d = {b}^{2} - 4ac \\ d = ( - 5) {}^{2} - 4 \times 6 \times ( - 4) = 25 + 96 = 121 \\ x12 = \frac{ - b + - \sqrt{d} }{2a} \\ x12 = \frac{5 + - 11}{12} \\ \frac{5 - 11}{12} = - \frac{ 6}{12} = - \frac{1}{2} = - 0.5 \\ \frac{5 + 11}{12} = \frac{16}{12} = \frac{4}{3}$
Б)
${x}^{4} - 4 {x}^{2} - 45 = 0 \\ t {}^{2} - 4t - 45 = 0 \\ d = {b}^{2} - 4ac \\ d = ( - 4) {}^{2} - 4 \times 1 \times ( - 45) = 16 + 180 = 196 \\ t12 = \frac{ - b + - \sqrt{d} }{2a} \\ t1 2 = \frac{4 + - 14}{2} \\ \frac{4 - 14}{2} = - \frac{10}{2} = - 5 \\ \frac{4 + 14}{2} = \frac{18}{2} = 9 \\ {x}^{2} = 9 \\ {x}^{2} = - 5 \\ x = 3 \\ x = - 3$