You have not provided the rest of the question. However, I'll tell you some information regarding the given line which you may use in solving your question.
Te general form of the linear line is:
y = mx + c
where:
m is the slope of the line
c is the y-intercept of the line (value of y at x = 0)
Now, the given line is:
x + y = 4
Putting this in the standardized form:
y = -x + 4
Comparing this with the general form, we would find that:
slope of line (m) = -1
y-intercept of line (c) = 4
The graph of the line is shown in the attached image.
Hope this helps :)