At \(x=3\), both rules give six, so the graphs meet at \((3,6)\).

At \(x=1\), the outputs are two and four. At \(x=5\), they are ten and eight.

The graph of \(y=2x\) rises more for each unit increase in input.

Answer

They intersect at \((3,6)\). At one, \(y=x+3\) is higher; at five, \(y=2x\) is higher.