Question 1044448
4x^3/(x^2+3)
=====4x
x^2+3/4x^3   
=====4x^3+12x
change signs and subtract
========-12x,
remainder is  -12x/(x^2+3)
4x -12x/(x^2+3).
Check by multiplying quotient by divisor
4x(x^2+3)-12x=4x^3.