(x³ -7x² +4x+12)/(x² - 7x+12) ≥ x +1;
(x³ -7x² +12x-8x+12)/(x² - 7x+12) ≥ x +1 ;
(x(x² -7x +12)-(8x-12))/(x² - 7x+12) ≥ x +1 ;
x(x² - 7x+12)/(x² - 7x+12) -(8x-12)/(x² - 7x+12) ≥ x+1 ;
x - (8x-12)/(x² - 7x+12) ≥ x+1 ;
1+(8x-12)/(x² - 7x+12) ≤0;
x(x+1)/(x-3)(x-4) ≤0 ; * * * x² - 7x+12=(x -3)(x-4) * * *
методом интервалов :
+ - + - +
----------[ -1 ] ------- [ 0 ] ---------- (3)---------(4) -----------
x ∈[- 1 ; 0) U (3 ;4) .