Final answer:
Lady Macbeth advises Macbeth to appear innocent while harboring deceitful intentions, and takes the lead in planning King Duncan's murder.
Step-by-step explanation:
Lady Macbeth provides crucial advice to Macbeth in Shakespeare's play. Upon his return home, she tells him to project an image of innocence while hiding his true intentions, as she plots the murder of King Duncan. Lady Macbeth essentially advises Macbeth to look like the innocent flower, but be the serpent under it. She insists that they can't fail if they are resolute and carefully manage their facades. Additionally, she takes charge of the preparations for Duncan's murder, telling Macbeth to leave everything to her and assuring him that she will drug the king's guards, making it easier to commit the murder. Her guidance underscores themes of deception and ruthlessness.