How do you multiply #(9a +2) (9a^2 + a + 1)#?

1 Answer
Aug 23, 2015

#=color(blue)(81a^3 + 27a^2 +11a+2#

Explanation:

#color(blue)((9a+2))(9a^2+a+1)#
#=color(blue)((9a)) *(9a^2+a+1) +color(blue)((2)) . (9a^2+a+1)#

note : #color(blue)(a^m*a^n=a^(m+n)#, is the property applied to exponents of #a#

#=81a^3 +9a^2 +9a + 18a^2 +2a +2#

Adding like terms

#=color(blue)(81a^3 + 27a^2 +11a+2#