Tính: d) 4x2y – 2xy2 + 8 – (3x2y + 9xy2 – 12xy + 6).
Tính:
d) 4x2y – 2xy2 + 8 – (3x2y + 9xy2 – 12xy + 6).
Tính:
d) 4x2y – 2xy2 + 8 – (3x2y + 9xy2 – 12xy + 6).
d) 4x2y – 2xy2 + 8 – (3x2y + 9xy2 – 12xy + 6).
= 4x2y – 2xy2 + 8 – 3x2y – 9xy2 + 12xy – 6
= (4x2y – 3x2y) + (– 2xy2 – 9xy2) + (8 – 6) + 12xy
= x2y – 11xy2 + 2 + 12xy.