Answer:
3x+4
Step-by-step explanation:
<span>The correct answer is 6.
The clearest way to determine this is by creating a table of possible hand shaking. If we label the people A-D, the following are the ways they can be combined:
AB
AC
AD
BC
BD
CD
There are no other combinations. </span>
The answer is A, not sure about the expression though. Sorry