Answer
(a) $right$, $left$.
(b) $upward$, $downward$.
Work Step by Step
(a) If we replace $x$ by $x-3$, we will need higher ($+3$ units) $x$ values to reach the same $y$ value, and the graph of the equation is shift to the $right$ by 3 units. On the other hand, if we replace $x$ by $x+3$, we will need less ($-3$ units) $x$ values to reach the same $y$ value, and the graph of the equation is shifted to the $left$ by 3 units.
(b) If we replace $y$ by $y-1$, we will need more ($+1$ unit) $y$ value to reach the original position, and the graph of the equation is shifted $upward$ by 1 unit. On the other hand, if we replace $y$ by $y+1$, the graph of the equation is shifted $downward$ by 1 unit.
