A. The first step to solve this question is to find the slope of the linear function, to do it, use the following formula:

Replace for the given values, y2 has a value of 141400, y1 a value of 11450, x2 is 0 and x1 a value of 23:

The y intercept is 141400, which is the value of the function when x=0.
Now, we can write the function of the value of the bulldozer in slope intercept form, this way:

B. To find the value of the bulldozer, replace t for 17 and solve:

According to this, after 17 years the bulldozer will have a value of $43350.