RĂ©ponse :
Explications Ă©tape par Ă©tape
Bonsoir
1)(2x - 1)/(x + 1) + 2 =
= (2x - 1)/(x + 1) + 2(x + 1)/(x + 1)
= (2x - 1 + 2x + 2)/(x + 1)
= (4x + 1)/(x + 1)
2) tableau de signe de (2x - 1)/(x + 1)
2x - 1 = 0
2x = 1
x = 1/2
x..........|-inf...............(-1)..............(1/2)...........+inf
2x-1....|.........(-)..................(-).........o......(+)...........
x+1......|.........(-)..........||......(+)................(+)...........
Eq.......|.........(+).........||......(-)..........o.....(+)...........
3) résoudre :
(2x - 1)/(x + 1) [tex]\ge -2[/tex]
(4x + 1)/(x + 1) [tex]\ge[/tex] 0
4x + 1 = 0
4x = -1
x = -1/4
x...........|-inf.............(-1).............(-1/4)...........+inf
4x+1.....|.........(-)..............(-)..........o......(+)...........
x+1.......|..........(-)........||....(+)..................(+)..........
Ineq....|...........(+)......||.....(-)..........o......(+)..........
[tex]x \in ]-\infty ; -1 [ U [ -1/4 ; +\infty [[/tex]