Answer:
y=-2/3 x + 3
Step-by-step explanation
in the form y=mx + b
b is the y intercept, therefore on the graph the y intercept is 3 and b will be 3.
we now have y =mx + 3
Then, you know the gradient (m) is negative because going down, therfore the only equation that has a negative gradient and the y intercept as 3 is the third one.
Therfore, the answer is y=-2/3x+3