Resposta:
a)3.x+2.(x+1)+x²=
[tex]3x + 2x + 2 + {x}^{2} \\ {x}^{2} + 5x + 2[/tex]
b)3.(x+y+z)-3.x-3.y-3.z=
[tex]3x + 3y + 3z - 3x - 3y - 3z \\ = 0[/tex]
