Resposta:
[tex]\frac{x+2}{7}=\frac{3x-6}{9}\\\\\left(x+2\right)\cdot \:9=7\left(3x-6\right)\\\\9x+18=21x-42\\\\9x+18-18=21x-42-18\\\\9x=21x-60\\\\9x-21x=21x-60-21x\\\\-12x=-60\\\\\frac{-12x}{-12}=\frac{-60}{-12}\\\\x=5[/tex]
