Explain How the Graph Of $y = - 4 \cdot 3 ^ { x } \text { can be obtained from the graph of } y = 3 ^ { x } \text {. }$

Explain how the graph of $y = - 4 \cdot 3 ^ { x } \text { can be obtained from the graph of } y = 3 ^ { x } \text {. }$