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BiaCocoş
a fost răspuns

|x-8|=0
|x+18|=0
|x-3|+|x la puterea 2 -9|=

Va rog ,macar primele doua.

Răspuns :

19999991
[tex] \star) |x - 8| = 0[/tex]

[tex]1)x - 8 = 0[/tex]

[tex]x = 8[/tex]

[tex]2) - x + 8 = 0[/tex]

[tex] - x = - 8 \: | \times ( - 1)[/tex]

[tex]x = 8[/tex]

[tex] \star) |x + 18| = 0[/tex]

[tex]1)x + 18 = 0[/tex]

[tex]x = - 18[/tex]

[tex]2) - x - 18 = 0[/tex]

[tex] - x = 18 \: | \times ( - 1)[/tex]

[tex]x = - 18[/tex]

[tex] \star) |x - 3| + | {x}^{2} - 9| = 0[/tex]

[tex]1)x - 3 + {x}^{2} - 9 = 0[/tex]

[tex]x - 3 + (x - 3)(x + 3) = 0[/tex]

[tex](x - 3)(1 + x + 3) = 0[/tex]

[tex](x - 3)(x + 4) = 0[/tex]

[tex] = > x - 3 = 0 = > x = 3[/tex]

[tex] = > x + 4 = 0 = > x = - 4[/tex]

[tex]2) - x + 3 - {x}^{2} + 9 = 0[/tex]

[tex] - {x}^{2} - x + 12 = 0 \: | \times ( - 1)[/tex]

[tex] {x}^{2} + x - 12 = 0[/tex]

[tex]a = 1[/tex]

[tex]b = 1[/tex]

[tex]c = - 12[/tex]

[tex]\Delta = {b}^{2} - 4ac[/tex]

[tex]\Delta = {1}^{2} - 4 \times 1 \times ( - 12)[/tex]

[tex]\Delta = 1 + 48[/tex]

[tex]\Delta = 49[/tex]

[tex]x_{1,2}=\frac{-b\pm\sqrt{\Delta}}{2a}[/tex]

[tex]x_{1,2}=\frac{-1\pm\sqrt{49}}{2 \times 1}[/tex]

[tex]x_{1,2}=\frac{-1\pm7}{2}[/tex]

[tex]x_{1}=\frac{-1 + 7}{2}[/tex]

[tex]x_{1}= \frac{6}{2} [/tex]

[tex]x_{1}=3[/tex]

[tex]x_{2}=\frac{-1 - 7}{2}[/tex]

[tex]x_{2}= - \frac{8}{2}[/tex]

[tex]x_{2}= - 4[/tex]

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