There is a linear function with a y-intercept of 3 and a x-intercept of 2. Determine the function expression of f shown in the figure.

Please directly answer the question and provide the final value, e.g., 1, 2.5, 300.
Question: There is a linear function with a y-intercept of 3 and a x-intercept of 2. Determine the function expression of f shown in the figure.

Please first conduct reasoning, and then answer the question and provide the final value, e.g., 1, 2.5, 300, at the end.
Question: There is a linear function with a y-intercept of 3 and a x-intercept of 2. Determine the function expression of f shown in the figure.
