The axis of symmetry of a graph is the vertical line x=5. One of the x-intercepts is (11,0). What is the other x-intercept. Explain how to do this either by showing work or how to enter it into the TI83Plus. Up until now I've had equations to work with so this one has me stumped.

symmetry means that your graph on one side is equal to that on the other side of the axis of symmetry.

so look at x=5 as the "centre".
How far is 11 from 5 ? to the right 6 units.
now move 6 units to the left from 5.
That would be (-1,0)