Answer:
Yes 
Step-by-step explanation:
Slope intercept form is: 
y=mx+b 
where m is the slope, and b is the y intercept 
We are given the slope, it is -3. We are also given the y intercept, (0,4). In this form, the 0 in (0,4) is ignored, and our y intercept is considered to be 4. 
Therefore, m is -3, and b is 4. 
y=mx+b 
y=-3x+4 
So, your answer is correct.