1) a(a+2b)-(b+a)^2=a^2+2ab-(a^2+2ab+b^2)=a^2+2ab-a^2-2ab-b^2=-b^2
2) 3(b-1)^2+8b=3(b^2-2b+1)+8b=3b^2-6b+3+8b=3b^2+2b+3
3) (m+4)^2-(m-3)*(m+3)=m^2+8m+16-m^2+9=8m+25
1) a(a+2b)-(b+a)^2=a^2+2ab-(a^2+2ab+b^2)=a^2+2ab-a^2-2ab-b^2=-b^2
2) 3(b-1)^2+8b=3(b^2-2b+1)+8b=3b^2-6b+3+8b=3b^2+2b+3
3) (m+4)^2-(m-3)*(m+3)=m^2+8m+16-m^2+9=8m+25