Question 352551
Here is a link to help with long division.
http://www.calc101.com/webMathematica/long-divide.jsp#topdoit

But this problem can be solved by factoring
{{{(48x^5+24x^4-18x^3)/(6x^2)}}}
{{{((6x^2)(8x^3 + 4x^2 - 3x))/(6x^2)}}}
{{{(8x^3 + 4x^2 - 3x)}}}
{{{x(8x^2 + 4x - 3)}}}
You can further factor the quadractic using the quadratic equation
*[invoke quadratic "x", 8, 4, -3 ]