Răspuns :
x^2-3x+3x-9=5-x^2-2x+2x-4
x^2-9=5-x^2-4
x^2-9-5+x^2+4=
x^2-14+x^2+4=
x^2+x^2-10=
2x^2-10=x^2(1-10)
-9x^2=0
x^2=[tex] \sqrt{9} [/tex]
x=3
x^2-9=5-x^2-4
x^2-9-5+x^2+4=
x^2-14+x^2+4=
x^2+x^2-10=
2x^2-10=x^2(1-10)
-9x^2=0
x^2=[tex] \sqrt{9} [/tex]
x=3
x la a doua -9=5-x la a doua +4
2x la a doua =18
x la a doua=9
x=3
2x la a doua =18
x la a doua=9
x=3