Плиз помогите мне пожалуйста!!! Дам 20 баллов!!!

1) a(a-2b)-(3b+a)^2=a^2-2ab-(9b^2+6ab+a^2)=a^2-2ab-9b^2-6ab-a^2=-8ab-9b^2=-b(8a+9b)

3) 3(b-10)^2+8b-5b^2=3(b^2-20b+100)+8b-5b^2=3b^2-60b+300+8b-5b^2=-2b^2+68b+300=-2(b^2-34b-150)

5) 4c(9c-3)-(6c+1)^2=36c^2-12c-(36c^2+12c+1)=36c^2-12c-36c^2-12c-1=-24c-1

2) (m+8)^2-(m-2n)(m+2n)=m^2+16m+64-(m^2-4n^2)=m^2+16m+64-m^2+4n^2=16m+64+4n^2=4 (4m+16+n^2)

4) (n+15)^2-n(n-19)=n^2+30n+225-n^2+19n=48n+225=3 (16n+75)

6) (6-5m)(5m+6)+(5m-4)^2=(6-5m)(6+5m)+25m^2-40m+16=36-25m^2+25m^2-40m+16=52-40m=4(13-10m)