Question

Уравнение: lg^2 * x - 3lg(10x)=1

Answer 1

$lg^2 x - 3lg(10x) = 1\ lg^2 x - 3lg10-3lgx = 1\ lg^2 x - 3lg x - 4 = 0\ lg x = t\ t^2 -3t - 4 = 0\ D = 9 +16 =25\ t_1 = (3+5)/2 = 4\ t_2 = (3-5)/2 = -1\ lg x = 4, x = 10000\ lg x = -1, x = 1/10$