(lg100 + lgx)² + (lg10 + lgx)² = 14 - lgx
(2 + lgx)² + (1 + lgx)² = 14 - lgx
4 +lg²x + 4lgx + 1 + 2lgx + lg²x + lgx - 14 = 0
2lg²x + 7lgx - 9 = 0
lgx = t
2t² + 7t - 9=0
D = 49 + 72 = 121
t = 1 t = -9/2
lgx = 1 lgx = -9/2
x = 10 x = 10^(-9/2) = 1 / √(10^9)
10 в степени -9/2