Answer:
6x+3y
Step-by-step explanation:
3x+3[x+y]
Distribute
3x+3x+3y
Combine like terms
[tex] = 3x + 3(x + y)[/tex]
[tex] = 3x + 3.x + 3.y[/tex]
[tex] = 3x + 3x + 3y[/tex]
[tex] = (3 + 3)x + 3y[/tex]
[tex] = 6x + 3y[/tex]
