Answer
See explanations.
Work Step by Step
When subtracting two polynomials, change the signs of the coefficient of the second polynomial and add up like terms to form a new polynomial. For example
$2x^3+3x^2+2x+1-(x^3+2x^2+x+1)=2x^3+3x^2+2x+1-x^3-2x^2-x-1=x^3+x^2+x$
