What is the difference of the polynomials? (8r^6s^3 – 9r^5s^4 + 3r^4s^5) – (2r^4s^5 – 5r^3s^6 – 4r^5s^4)

(8r^6s^3 – 9r^5s^4 + 3r^4s^5) – (2r^4s^5 – 5r^3s^6 – 4r^5s^4)
= 8r^6s^3 – 9r^5s^4 + 3r^4s^5 – 2r^4s^5 +  5r^3s^6 + 4r^5s^4
= 8r^6s^3 – 9r^5s^4 +  4r^5s^4 + 3r^4s^5 – 2r^4s^5 +  5r^3s^6 
= 8r^6s^3 – 5r^5s^4 + r^4s^5  +  5r^3s^6 

Hope it helps