Precalculus (6th Edition)

$$3x^{4}-4x^{2}+5$$
Initial equation: $$(x^{4}-3x^{2}+2)-(-2x^{4}+x^{2}-3)$$ Start by distributing the negative to the second set of parenthesis that indicates subtraction: $$x^{4}-3x^{2}+2+2x^{4}-x^{2}+3$$ Finally, combine like terms to arrive at the final answer: $$3x^{4}-4x^{2}+5$$