<PRE><B>Question 194307</B>
(5r^3-6rs+3s^2)-(-5r^3-3rs+4s^2) 



5r^3-6rs+3s^2+5r^3+3rs-4s^2



10r^3-3rs-s^2



Ans: (5r^3-6rs+3s^2)-(-5r^3-3rs+4s^2) = 10r^3-3rs-s^2</PRE>