f)
=-(4ab-4a^2+b^2-ab)-4a^2+b^2=
=-4ab+4a^2-b^2+ab-4a^2+b^2=-3ab
=-3*0,25*(-2)=1,5
j)
=-(4ab-16a^2+b^2-4ab)-16a^2+2b^2=
=16a^2-b^2-16a^2+2b^2=
=b^2=(-2)^2=4