c) (4x -1)( 6y+1)- 3x(8x +4/3);
Giải thích
c) (4x−1)(6y+1)−3x8x+43
=4x . 6y+4x . 1−1 . 6y−1 . 1−3x . 8x−3x . 43
= 24xy + 4x – 6y – 1 – 24x2 – 4x
= 24xy – 24x2 + (4x – 4x) – 6y – 1
= 24xy – 24x2 – 6y – 1.
c) (4x−1)(6y+1)−3x8x+43
=4x . 6y+4x . 1−1 . 6y−1 . 1−3x . 8x−3x . 43
= 24xy + 4x – 6y – 1 – 24x2 – 4x
= 24xy – 24x2 + (4x – 4x) – 6y – 1
= 24xy – 24x2 – 6y – 1.