Срочнооо!! Помогите!! 14x^2-5x-1=0

Question

Срочнооо!! Помогите!!
14x^2-5x-1=0

Answer 1

14x² - 5x - 1 = 0
D = 25 + 56 = 81 ; √ D = 9
x1 = ( 5 + 9 ) : 28 = 14/28 = 0,5 
x2 = ( 5 - 9 ) : 28 = - 4/28 = - 1/7