Let's simplify step-by-step. 4x^3−3x^2+x+3x^3=4x^3+−3x^2+x+3x^3
Combine Like Terms: =4x^3+−3x^2+x+3x^3
= (4x^3+3x^3)+(−3x^2)+(x)=7x^3+−3x^2+x
Answer: =7x^3−3x^2+x
