Question

Rezolvați ecuația : lg^{2} x-3lgx+2=0

Answer 1

$lg^{2}x-3lgx+2=0$

$lgx = t$

${t}^{2} - 3t + 2 = 0$

${t}^{2} - 2t - t + 2 = 0$

$t(t - 2) - (t - 2) = 0$

$(t - 2)(t - 1) = 0$

$= > t- 2 = 0 = > t= 2$

$t = lgx = > lgx = 2 = > x = 100$

$= > t- 1 = 0 = > t = 1$

$t = lgx = > lgx = 1 = > x = 10$