To find the slope, we use two points from the table (-3, 1.5) and (0,3).-
Now, we use the slope formula

Replacing the points, we have

The slope is 5/6.
On the other hand, the starting point refers to the initial condition or the y-intercept which is given by the point (0,3).
Therefore, the starting point is 3.
At last, the equation would be

Remember that the slope must be a coefficient of x, and the starting point is the independent term.