Recognize the type of expression and use an appropriate method to factor it:
\[
x^{3}+14 x^{2}+49 x
\]
Identify the common factor
The expression \(x^{3}+14 x^{2}+49 x\) has a common factor of \(x\) in all terms.
Factor out the common factor
Factor out \(x\) from the expression:
\[
x(x^{2} + 14x + 49)
\]
Factor the quadratic expression
The quadratic expression \(x^{2} + 14x + 49\) is a perfect square trinomial. It can be factored as:
\[
(x + 7)^2
\]
Write the fully factored form
Combine the results to write the fully factored form of the original expression:
\[
x(x + 7)^2
\]
The factored form of the expression is \(\boxed{x(x + 7)^2}\).
The factored form of the expression is \(\boxed{x(x + 7)^2}\).