Answer:
y = -.75 x
Step-by-step explanation:
To determine if y varies directly with x, we look at y/x and see if it is a constant
y/x = 2.25/-3 = -.75
= -.75/1 = -.75
=-3/4 = -.75
Since it is a constant, it has direct variation. The constant of variation is -.75
y = -.75 x