Answer:
Pedro: are the same line, infinitely many
Amy: is
Matt: always, infinitely many
Explanation:
PEDRO: Since the lines are on top of one another, there are infinitely many solutions. These lines are called coinciding lines.
AMY: 3y = 6x + 6 is a multiple of y = 2x + 2. When one equation is a multiple of the other, there are infinitely many solutions to the system.
MATT: When the equation 3y = 6x + 6 is divided by 3, the quotient is equal to the first equation. The equations are equivalent, so they describe the same graphed line.