Let us solve the given equation by long divisions of polynomial method
3a2−2ab−b2−4a−2b4
2a3+3a2b−b3)¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯6a5+5a4b−8a3b2−6a2b3−6ab4
6a5+9a4b−0a3b2−3a2b3
(−)(−)(+)(+)–––––––––––––––––––––––––––––––
−4a4b−8a3b2−3a2b3−6ab4
−4a4b−6a3b2+0a2b3+2ab4
(+)(+)(−)(−)–––––––––––––––––––––––––––––––
−2a3b2−3a2b3−8ab4
−2a3b2−3a2b3+0ab4+b5
(+)(+)(−)(−)––––––––––––––––––––––––––
−8ab4−b5
−8ab4−12b5+4a−2b7
(+)(+)(−)––––––––––––––––––––––––
11b5−4a−2b7
Since quotient upto four terms is asked, we stop the further division
hence, quotient is 3a2−2ab−b2−4a−2b4
and remainder is 11b5−4a−2b7