Bom Dia !!!
[tex]3x - 2(x - 5) + x + 3 = 20\\\\3x - 2x + 10 + x + 3 = 20\\\\2x = 20 - 10 - 3\\\\2x = 7\\\\{\boxed{\sf x = \frac{7}{2}}} \\\\ou\\\\{\boxed{\sf x = 3,5}[/tex]
Espero ter ajudado :-)
Att: LDC
