Question

Помогите 15 баллов даю а)5x^2+0,2x=0 б)5x^2-6x+1=0 в) 3x(3x-2)+7=6

Answer 1

$a)5 {x}^{2} + 0.2x = 0 \ x(5x + 0.2) = 0 \ x1 = 0 \ 5x + 0.2 = 0 \ x2 = - 0.2 div 5 \ x2 = - 0.04 \ b)5 {x}^{2} - 6x + 1 = 0 \ d = 36 - 20 = 16 \ x1 = frac{6 + 4}{10} = 1 \ x2 = frac{6 - 4}{10} = frac{1}{5} = 0.2 \ c)3x(3x - 2) + 7 = 6 \ 9 {x}^{2} - 6x + 1 = 0 \ ( {3x - 1)}^{2} = 0 \ 3x - 1 = 0 \ x = frac{1}{3}$