How has the friendship between Macbeth and Banquo changed in act 1 scene 3 and act 3 scene 1?please get back to me quickly please. before tonight...

Macbeth & Banquo, the two generals of King Duncan, fought together against the rebels & the invaders to win great admiration from the king & the people of Scotland. In act1 sc.3, we see them together on a heath where the witches appear to hail Macbeth first as the thane of Glamis, then as the thane of Cawdor, and finally as the future king of Scotland. Before disappearing, the witches also sound prophetic towards Banquo:'Thou shalt get kings, though thou be none'. It is Banquo who first sees the witches & doubt their bonafides; it is Banquo who expresses surprise to see the strange effect of the witches' proclamations on Macbeth:'Good sir, why do you start, and seem to fear/Things that do soundso fair?' Banquo regards the witches as bubble-like creatures & inclined to evil having deceitful attributes; he warns his friend & compatriot against their alluring harms as he himself looks rather sceptical about what they say. When Ross & Angus make their appearance, and the former communicates to Macbeth the king's decision to confer the title of Cawdor on Macbeth, Banquo ventilates his surprise:'What! can the devil speak true?' Thus it appears that Banquo is a good friend of Macbeth & as a watchful man of conscience warns Macbeth against supernatural temptaion.

But Banquo's soliloquy at the beginning of act3 sc.1 reveals that he too is about to fall a victim to the witches' temptation. If Macbeth has attained all that the witches had predicted for him, why should not Banquo hope that the witches' prophecies about him also should come true? Macbeth & Lady Macbeth  appear as king & queen, and cordially invite Banquo as the chief guest at the coronation banquet. As Banquo leaves  on some piece of business & all else depart, Macbeth contemplates on the elimination of Banquo for he fears Banquo's 'royalty of nature'; he suffers from a sense of inferiority in the noble presence of Banquo, and he fears that Banquo may commit the same heinous act to realise the prophecy as he himself did  to usurp the throne. Macbeth seems to be very agitated & unsettled; he must now kill both Banquo & his son, Fleance, for his future safety & security. Macbeth meets two of the wretches who will kill Banquo & Fleance.

Macbeth-Banquo friendship thus undergoes serious changes. Macbeth, tortured by his sense of guilt & fear, desperately looks for a bloody solution & Banquo is, as it were, a friend -turned-foe.