For f(x) to be zero, we have the following relation:

Solving for x:

The x-intercept is the point at which the graph crosses the x-axis, which is also the solution for the equation "f(x) = 0".
The zero of a function is any replacement for the variable that will produce an answer of zero, which again, is also the solution of "f(x) = 0" and the x-intercept.
The answer for all of them is the same, x = 7.