Plot the influence line for the moment at Cof the beam shown below. What is the equation of the influence line from point A to C?  Establish the origin such that x is measured from point A (e.g. at A, x = 0; at B, x = 12 ft).

Plot the influence line for the moment at Cof the beam shown below. What is the equation of the influence line from point A to C?  Establish the origin such that x is measured from point A (e.g. at A, x = 0; at B, x = 12 ft).