Answer
$$8x^5-18x^4+5x^2+1.$$
Work Step by Step
We subtract the $x^5$-terms as follows
$$
12x^5-4x^5=8x^5
$$
then subtract the $x^4$-terms as follows
$$
-13x^4-5x^4=-18x^4
$$
then subtract the $x^2$-terms as follows
$$
7x^2-2x^2=5x^2
$$
then subtract the constant terms as follows
$$
0+1=1
$$
Hence the result is
$$8x^5-18x^4+5x^2+1.$$
