Start by setting synthetic division up:
6 | 3 5 6
Bring the 3 down,
6 | 3 5 6
3
Multiply, rinse and repeat:
6 | 3 5 6
18 138
3 23 144
Separate one term from the right, since this is vanilla synthetic division:
6 | 3 5 6
18 138
3 23 || 144
Use the appropriate polynomial rules to build your equation from there:
3x + 23 + (144/x+6)
As for the quotient I would assume it is referring to the remainder, which is 144/x+6, but that is probably a better thing for you to decide than me.