Answer:
The two factors which influenced Macbeth's decision to kill King Duncan are:
Duncan’s decision to name Malcolm as his successor
the witches’ prophecy about Macbeth's future
Step-by-step explanation:
After hearing the prophecy about Macbeth's future from the three witches, Macbeth grows the greed inside his mind. He becomes very ambitious and plans to kill King Duncan in the assistance of his wife Lady Macbeth.