Answer:
-4x^4+x^2+6
Step-by-step explanation:
[tex]\left(-4x^4+6x^2+3\right)-\left(5x^2-3\right)\\\\\mathrm{Remove\:parentheses}:\quad \left(-a\right)=-a\\=-4x^4+6x^2+3-\left(5x^2-3\right)\\\\-\left(5x^2-3\right):\quad -5x^2+3\\\\=-4x^4+6x^2+3-5x^2+3\\\\\mathrm{Simplify}\:-4x^4+6x^2+3-5x^2+3:\\\quad -4x^4+x^2+6[/tex]
