Which of the following function rules represents the graph shown? f(x) = x - 3 f(x) = 3 - x f(x) = -3x

As the line raises from left to right, the slope must be positive, so only the function, f(x)=x-3, has a slope greater than zero. Additionally, at x=0, the y-value is at, or around, -3, confirming that f(x)=x-3 is the correct solution.