24/(х-7) - 6/х = 3
приводим к общему знаменателю х(х-7)
24х/(х(х-7)) - (6(х-7))/(х(х-7)) = (3х(х-7))/(х(х-7))
(24х-6х+42-3х²+21х)/(х(х-7)) = 0
(39х+42-3х²)/(х(х-7)) = 0
ОДЗ: х(х-7)≠0; х≠0; х≠7
39х+42-3х²=0 (: -3)
х²-13х-14=0
D=169+56=225
x₁ = (13-15) / 2 = -1
x₂ = (13+15) / 2 = 14
Ответ: х₁= -1; х₂ = 14