Answer:
[tex] \displaystyle \large{x(7 {x}^{2} + 4)}[/tex]
Step-by-step explanation:
We are given the cubic expression:
[tex] \displaystyle \large{7 {x}^{3} + 4x}[/tex]
In the expression, there exists same x-term but not like term.
Factor using LCF (Least Common Factor which is x)
[tex] \displaystyle \large{x(7 {x}^{2} + 4)}[/tex]
From 7x^2+4, the expression is not factorable and thus:-
[tex] \displaystyle \large{x(7 {x}^{2} + 4)}[/tex]
is the simplified form.