How much greater is #(20x^7 - 10x^6 - 9x^5 - 14x^4 + 18x) + (-6x^6 - 12x^5 - 9x^4 - 9x)#?

1 Answer

#=20x^7-16x^6-21x^5-23x^4+9x#

Explanation:

#(20x^7-10x^6-9x^5-14x^4+18x) + (-6x^6-12x^5-9x^4-9x)#
Index Coefficient
7 --------------#(+20+0) =+20#
6 --------------#(-10-6)=-16#
5---------------#(-9-12)=-21#
4---------------#(-14-9)=-23#
1--------------- #(+18-9)=+9#
Thus,
#=20x^7-16x^6-21x^5-23x^4+9x#