(x-2/3)²+3=x-(1/3-x)(x+4/3)
x²-4x/3+4/9+3=x-(x/3+4/9-x²-4x/3)
x²-4x/3+31/9=x-(-x²-3x/3+4/9)
x²-4x/3-x=-31/9+x²+x-4/9
x²-x²-4x/3-x-x=-35/9
-4x/3-2x=-35/9 aducem la acelasi numitor
(-4x-6x)/3=-35/9
-10x/3=-35/9 inmultim cu -1
9·10x=35·3
x=105/90 simplificam
x=7/6
