99x³ - ( 1 + 5x) (1 -5x + 25x^2) ≥ 12x - 26x³
99x³ - ( 1 ³+ (5x)³ ≥ 12x - 26x³
99x³ - 1 - 125x³- 12x +26x³ ≥ 0
-1 -12х ≥0
12х ≤ -1
х ≤ -1/12
х∈(-∞ ; -1/2]
99x³ - ( 1 + 5x) (1 -5x + 25x^2) ≥ 12x - 26x³
99x³ - ( 1 ³+ (5x)³ ≥ 12x - 26x³
99x³ - 1 - 125x³- 12x +26x³ ≥ 0
-1 -12х ≥0
12х ≤ -1
х ≤ -1/12
х∈(-∞ ; -1/2]