5x в квадрате -3x-2=0
5x^2 - 3x - 2 = 0 D = 9 + 4*2*5 = 9 + 40 = 49 = 7^2 x1 = ( 3 + 7)/10 = 10/10 = 1 x2 = ( 3 - 7)/10 = - 4/10 = - 2/5