Hej!
a]
[tex]2a\cdot|a-3|=2\cdot(-4)\cdot|-4-3|=\\\\=-8\cdot|-7|=-8\cdot7=\boxed{-56}[/tex]
b]
[tex]|2a-3|\cdot(3+2a)=|2\cdot(-\sqrt3)-3|\cdot(3+2\cdot(-\sqrt3))=\\\\=|-2\sqrt3-3|\cdot(3-2\sqrt3)=(2\sqrt3+3)(3-2\sqrt3)=\\\\=3^2-(2\sqrt3)^2=9-12=\boxed{-3}[/tex]
