|x²-4x|=x+2
|x²-4x|=x²-4x; x²-4x≥0
x(x-4) ≥0 pentru x∈(-∞;0]U[4; ∞)
|x²-4x|= -x²+4x; x²-4x<0
x(x-4) <0 pentru x∈(0; 4)
1. x∈(-∞;0] U[4; ∞)
x²-4x=x+2
x²-5x-2=0
Δ=25+8=33
x1=(5+√33)/2
x2=(5-√33)/2
2. x∈(0;4)
-x²+4x=x+2
-x²+3x-2=0
x²-3x+2=0
Δ=9-8=1
x3=(3+1)/2=2
x4=(3-1)/2=1
S={(5-√33)/2; 1; 2; (5+√33)/2}
