Slope-intercept form: y = mx + b [m is the slope, b is the y-intercept, or the y value when x = 0 ---> (0, y)]
To find the equation's y-intercepts, you can rearrange the variables, and isolate/get y by itself
#1
cx + ay = b Subtract cx on both sides
ay = b - cx Divide a on both sides
(0, ) is your answer
Do the same for the rest, and you should get:
#2 (0, )
#3 (0, )
#4 (0, )