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)
${x}^{4} - 4 {x}^{2} - 45 = 0 \ t {}^{2} - 4t - 45 = 0 \ d = {b}^{2} - 4ac \ d = ( - 4) {}^{2} - 4 times 1 times ( - 45) = 16 + 180 = 196 \ t12 = frac{ - b + - sqrt{d} }{2a} \ t1 2 = frac{4 + - 14}{2} \ frac{4 - 14}{2} = - frac{10}{2} = - 5 \ frac{4 + 14}{2} = frac{18}{2} = 9 \ {x}^{2} = 9 \ {x}^{2} = - 5 \ x = 3 \ x = - 3$