Выражение 1) (2b-3) (4b+9) 3) 16m^2-(3-4m) (3+4m) 5)(х-4) (х+-8)^2

1) (2b-3)*(4b+9)=8b^2+18b-12b-27=8b^2+6b-27 3) 16m^2-(3-4m)*(3+4m)=16m^2-(9+12m-12m-16m^2)=16m^2-9+16m^2=32m^2-9 5)(x-4)*(x+4)-(x-8)^2= x^2-16-(x^2-16x+64)=x^2-16-x^2+16x-64= -80+16x