since h(-3)=3 then the line passes throught the point (-3,3) and by the same reasoning the line passes thought (0,2) too, then the slope of the line is
m=(3-2)/(-3-0)=-1/3
then the line equation is
[tex]h=-\frac{1}{3}x+2[/tex]then h(-6)=4 because:
[tex]h(-6)=-\frac{1}{3}(-6)+2=4[/tex]