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|3x+5|=8

vreau si eu rasp va rog


Răspuns :

|3x+5|=8 => 3x+5=8 sau -8

Cazul l:

3x+5=8 |-5

3x=3 |:3

x=1

Cazul ll:

3x+5=-8 |-5

3x=-13

[tex]x = - \frac{13}{3} [/tex]

[tex]raspuns : x = - \frac{13}{3} \: sau \: 1[/tex]

[tex]\it |3x+5|=8 \Rightarrow 3x+5=\pm8 \Rightarrow 3x+5\in\{-8,\ 8\}_{-5}\Rightarrow 3x\in\{-13,\ 3\}|_{:3}\Rightarrow\\ \\ \\ x\in\Big\{-\dfrac{13}{3},\ 1\Big\}[/tex]