Can anyone help here? I keep trying, but I can't get the right answer.
For a certain value of k, the system
3a + 4b = 7
6a + 4b = k + 3a
has infinitely many solutions (a,b). What is k?
Simplify 6a+4b=k+3a to get 3a+4b=k.
If:
3a+4b=k
and
3a+4b=7
then the two equations must be equal, so k=7.
+1347 
