x + 7 = 12
[tex]x = 12 - 7[/tex]
[tex]\boxed{x = 5}[/tex]
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x - 4 = 3
[tex]x = 3 + 4[/tex]
[tex]\boxed{x = 7}[/tex]
[tex]Espero \: haberte \: ayudado[/tex]
ATTE: OrekiHoutarou
