(2x+5)(6-3x) = 12x - + 30 - 15x = -3x - + 30
(3x+1)(1.2 + 5x) = 3.6x + + 1.2 + 5x = 8.6x + + 1.2
(m+n)(m-n) = - mn + mn - =
(x+2y-5)(4x+y) = + xy + 8xy + - 20x - 5y = + 9xy + - 20x - 5y
+ 30 - 15x = -3x - + 30
+ 1.2 + 5x = 8.6x + + 1.2
- mn + mn - 
= 
+ xy + 8xy + 
- 20x - 5y = + 9xy + - 20x - 5y
