What is the difference of the polynomials?

Answer:
[tex]2x^{3} + 2x[/tex]
Step-by-step explanation:
[tex](x^{4} + x^{3} + x^{2} + x) - (x^{4} - x^{3} + x^{2} - x)[/tex] --> Equation
[tex]x^{4} + x^{3} + x^{2} + x - x^{4} + x^{3} - x^{2} + x[/tex] --> Substituted the -1 on the second parentheses to successfully be able to subtract
[tex](x^{4} - x^{4}) + (x^{3} + x^{3}) + (x^{2} - x^{2}) + (x + x)[/tex] --> Combined Like Terms
[tex](0) + (2x^{3}) + (0) + (2x)[/tex] --> Simplified
[tex]2x^{3} + 2x[/tex] --> Simplified
Hope this helped! <3