Question 1110401
The x-intercept is the point on the graph of your function where it touches the x-axis (or just the x-coordinate of that point).
As the x-axis is the {{{y=0}}} line, you can find the x-coordinate by solving {{{5x-15=0}}} to get {{{x=3}}}.
That gives you the {{{x}}} value (the number of pets walked) to get a profit of {{{y=0}}} . You could call it your break-even point.
Until you have walked 3 dogs, you have spent more money to get your business going than what you have earned. After that , every dog you walk gives you a net profit.