What you must do for this case is to find the intersections of the line with the y axis and the x axis.
y = 3x + 9
We have then:
Axis y:
x = 0
y = 3 (0) +9
y = 9
X axis:
y = 0
0 = 3x + 9
x = -9 / 3 = -3
Answer:
The intersections of the line with the y axis and the x axis are nine and minus three, respectively.
