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2. Soluția reală a ecuației 2|2x + 1| - 1 = 13​

Răspuns :

|2x+1|=(13+1)/2
|2x+1|=14/2
|2x+1|=7
1.2x+1=7 => x=(7-1)/2 => x=6/2 => x=3
2. -2x-1=7 => x=(7+1)/(-2) => x=8/(-2) => x=-4

 

[tex]\displaystyle\bf\\2|2x + 1| - 1 = 13\\\\2|2x + 1| = 13+1\\\\2|2x + 1| = 14\\\\|2x + 1|=\frac{14}{2}\\\\|2x + 1|=7\\\\2x + 1=\pm7\\\\Ecuatia~1:\\\\2x + 1=7\\\\2x=7-1\\\\2x=6\\\\x=\frac{6}{2}\\\\\boxed{\bf x_1=3}\\\\\\Ecuatia~2:\\\\2x + 1=-7\\\\2x=-7-1\\\\2x=-8\\\\x=\frac{-8}{2}\\\\\boxed{\bf x_2=-4}[/tex]