2. a=2-V5
b= (V5+2)/(5-4) am rationalizat cu V5+2 => b= V5+2
Mg=V(2-V5)(V5+2)= V(2V5+4-5-2V5)= V(-1) = -1
3. -3 < 2x+1 </ 5 /-1
-4 < 2x </ 4 /:2
-2 < x </ 2 => A={-1,0,1,2}
B={-8,-4,-3,-2,2}
A ∩ B={2}
