1. (x+2) (x+3) 2.(2x+1) (2x-1) 3.(x-4) (-x-1)

1. (x+2) (x+3)
= x² + 3x + 2x + 6
= x² + 5x + 6.

2.(2x+1) (2x-1)
= 4x² - 2x + 2x - 1
= 4x² - 1.

3.(x-4) (-x-1)
= -x² - 1x + 4x + 4
= -x² + 3x + 4.