Can anyone help me to draw a 3d-plot, please?

Hi to all, I don't know the MATLAB language and I have to take my time to learn it, but now I 'd like to plot a 3d graph. Here it is: in the graph, I'd like to plot the line y=(x+5)/2, the sheaf of planes containing that line; not all the sheaf, but an image that makes the concept, like this:

and the point P(1,2,1). If anyone can help me with the code needed, I'll be very grateful.