A + B = (4x2 – 5xy + 3y2) + (3x2 + 2xy - y2)
= 4x2 – 5xy + 3y2 + 3x2 + 2xy - y2
= (4x2 + 3x2) + (-5xy + 2xy) + (3y2 - y2)
= 7x2 - 3xy + 2y2
Bậc: 2
A - B = (4x2 – 5xy + 3y2) - (3x2 + 2xy - y2)
= 4x2 – 5xy + 3y2 - 3x2 - 2xy + y2
= (4x2 - 3x2) + (-5xy - 2xy) + (3y2 + y2)
= x2 - 7xy + 4y2
Bậc 2