Suppose that an object moves along the $y$-axis so that its location is $y = x^2 + 3x$ at time $x$. (Here $y$ is in meters and $x$ is in seconds.)

(A) Find the average velocity (the average rate of change of $y$ with respect to $x$) for $x$ changing from 2 to 7 seconds. Don't forget to include units in all your answers.
Average velocity =

(B) Find the average velocity for $x$ changing from $6$ to $6 + h$ seconds.
Average velocity =

(C) Find the instantaneous velocity at $x = 6$ seconds .
Instantaneous velocity =