Question

решите уравнения
a) x^2-x-1=0;
б) x/5 + 1/x =4

Answer 1

${x}^{2} - x - 1 = 0 \ d : = { (- 1)}^{2} - 4 times 1 times ( - 1) = 5 \ x = frac{ 1 frac{ + }{} sqrt{5} }{2}$
2.
$frac{x}{5} + frac{1}{x} = 4 \ х : : не : : равен : 0 \ frac {{x}^{2} }{5} + 1 = 4x \ {x}^{2} -20x + 5 = 0 \ d = 400 - 20 = 380 \ x = frac{20 frac{ + }{} 2sqrt{95} }{2} = 10 frac{ + }{ } sqrt{95}$