1) (1-а)(2+0)-(2+а)(1-в)= 2) (9m-2n)(2m+n)-(6m+n)(3m-2n)=

Question

1) (1-а)(2+0)-(2+а)(1-в)=
2) (9m-2n)(2m+n)-(6m+n)(3m-2n)=

Answer 1

1)
(1 - a)*2 - (2 + a)(1 - b) = 
= 2 - 2a - (2 - 2b + a - ab) = 
= 2 - 2a - 2 + 2b - a + ab = 
= - 3a + 2b + ab

2)
18m^2 + 9mn - 4mn - 2n^2 - (18m^2 - 12mn + 3mn - 2n^2) = 
= 18m^2 + 5mn - 2n^2 - (18m^2 - 9mn - 2n^2) = 
= 18m^2 + 5mn - 2n^2- 18m^2 + 9mn + 2n^2 = 
= 14mn