lg²100x - 7lgx >= 8
(lgx+lg100)²-7lgx >= 8
lg²x+4lgx+4-7lgx-8 >= 0
lg²x-3lgx-4 >= 0
lg²x+lgx-4lgx-4 >= 0
lgx(lgx+1)-4(lgx+1) >= 0
(lgx+1)(lgx-4) >= 0
+. -. +
------[-1]--------[4]------
[lg x <= -1</p>
[lg x >= 4
[0 < x <= 1/10</p>
[x >= 10000
Ответ: x€(0: 0.1)U[10000; + ∞)