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6. Rezolvaţi ecuația (x + 2)^2 = 6x +7,x € R.​

Răspuns :

[tex](x + 2) ^{2} = 6x + 7 \\ x ^{2} + 4x + 4 = 6x + 7 \\ {x}^{2 } - 2x - 3 = 0[/tex]

∆=b^2-4ac=(-2)^2-4×1×(-3)=4+12=16

[tex]x1 = \frac{ - b + \sqrt{16} }{2a} = \frac{2 + 4}{2} = \frac{6}{2} = 3[/tex]

[tex]x2 = \frac{ - b - \sqrt{16} }{2a} = \frac{2 - 4}{2} = \frac{ - 2}{2} = - 1[/tex]