(x²-4x+3)/(x²-49)≥0
x²-4x+3=0
x1+x2=4 U x1*x2=3⇒x1=1 U x2=3
x²-49=0
x²=49
x=+-7
+ _ + _ +
---------------(-7)--------------[1]-----------------[3]-------------------(7)----------------
x∈(-∞;-7) U [1;3] U (7;∞)
{x²+x-2≥0
{(x+3)/(x-4)≤0
1)x1+x2=-1 U x1*x2=-2⇒x1=-2 U x2=1
x≤-2 U x≥1
2)x=-3 x=4
-3≤x<4<br>x∈[-3;-2] U [1;4)