<PRE><B>Question 548535</B>
(7x^3 - 7x^2 - 1) - (9x^2 - x + 4)



7x^3 - 7x^2 - 1 - 9x^2 + x - 4



7x^3 - 16x^2 + x - 5



So (7x^3 - 7x^2 - 1) - (9x^2 - x + 4) = 7x^3 - 16x^2 + x - 5</PRE>