How would I use polynomial division to write the rational expression as a polynomial in descending powers?

SOLUTION
We want to perform the division and write our answer in descending powers
[tex]\frac{2x^4+5x^2-21x+24}{x^2+2x+4}[/tex]The expression above can be properly written as
[tex]\frac{2x^4+0x^3+5x^2-21x+24}{x^2+2x+4}[/tex]Perfoming the division we have
Step 3
Hence the answer in descending powers is
[tex]2x^2-4x+5\text{ Remaider }-15x+4[/tex]It can also be written as
[tex]2x^2-4x+5+\frac{-15x+4}{x^2+2x+4}[/tex]