Răspuns :
√(2x+3)=x
2x+3=x²
2x+3-x²=0
-x²+2x+3=0
Δ=(2)²-4*(-1)*3=4+12=16>0
x1=-2+√16/2=-2+4/2=2/2=1
x=-2-√16/2=-2-4/2=-6/2=-3.
Raspuns:-3 si 1.
Bafta!
x² = 2 x + 3
x ² - 2 x - 3 = 0
Δ = 4 + 12 = 16
x₁ = ( 2 + √16 ) / 2 = ( 2 + 4 ) / 2 = 6 / 2 = 3
x₂ = ( 2 - 4 ) / 2 = - 2 / 2 = - 1