No. 2(3 + x) is NOT equal to the expression 6 + 3x.
Here's how you can tell - work it out assuming that it would equal to 6 + 3x....Then, if you don't come out with the same expression, it doesn't equal it.
2(3 + x) = 6 + 3x
6 + 2x = 6 + 3x
See? If you work it out, it wouldn't be the same answer. The ACTUAL answer would be 6 + 2x NOT 3x.
Hope that helps! :)