Răspuns:
x ∈ [-1 ; 3]
Explicație pas cu pas:
(x-2)·(x+1) ≤ (x+1) <=>
(x-2)·(x+1) - (x+1) ≤ 0 <=>
(x+1)·(x-2-1) ≤ 0 <=>
(x+1)·(x-3) ≤ 0
x I -∞ -1 3 +∞
x+1 I ----------------0++++++++++++++
x-3 I-------------------------0++++++++
____________________________________
(x+1)·(x-3) I ++++++++++0-------0+++++++++
=> x ∈ [-1 ; 3]
