1-3х + 1+3х ≥ 12
1+3х 3х-1 1-9х²
1-3х + 1+3х - 12 ≥0
3х+1 3х-1 1-9х²
1-3х + 1+3х + 12 ≥0
3х+1 3х-1 9х²-1
1-3х + 1+3х + 12 ≥0
3х+1 3х-1 (3х-1)(3х+1)
(1-3х)(3х-1)+(1+3х)(3х+1)+12 ≥0
(3х-1)(3х+1)
-(3х-1)²+(3х+1)²+12 ≥ 0
(3х+1)(3х-1)
-(9х²-6х+1)+9х²+6х+1+12 ≥0
(3х+1)(3х-1)
-9х²+6х-1+9х²+6х+1+12 ≥0
(3х+1)(3х-1)
12х+12 ≥ 0
(3х+1)(3х-1)
12(х+1) ≥0
(3х+1)(3х-1)
{12(x+1)(3x+1)(3x-1) ≥0
{3x+1≠0
{3x-1≠0
{12 * 1 * 1 (x+1)(x+ 1 )(x - 1 ) ≥0
3 3 3 3
{x≠ - 1
3
{x≠ 1
3
(x+1)(x+ 1 )(x- 1 )≥0
3 3
x=-1 x=-1 x= 1
3 3
- + - +
----------- -1 ---------- - 1 ----------- 1 --------------
\\\\\\\\ 3 3 \\\\\\\\\\\\\\\\
x∈[-1; -1 )U ( 1 ; +∞)
3 3