Original Graph

moved a to positive 0.9-Right upper left quad shrank or shifted down  below the x axis. The lower right quad moved from above the x axis to  below the x axis.

moved b to negative 1.3 – Horizontal flips Shifts the upper left quad to the right and the bottom right quad to the left.

Moved c to positive 2.7 ( horizontal flip – i think is the right term but the graphs got shorter) 

Moved d to positive 1-flidped  vertically both quads and they shifted up 

I don't know that I have one that was easier than the other but if I  had to make a choice. I would chose moving d to a positive because you  can clearly see that the graphs were flipped vertically and shifted up  higher.  I could be wrong as I am still having trouble with functions.