Substract the expressions for P(x) and Q(x).
Substract like terms, which are the terms that have the same variable raised to the same power.
For this case, substract x^2 from x^2 and 3x from x:
[tex]\begin{gathered} x^2+x-(x^2+3x) \\ x^2-x^2+x-3x \\ -2x \end{gathered}[/tex]It means that the answer is -2x.
