How do you multiply #(- 3a + 7) ( - 6a + 3)#?

1 Answer
Nov 22, 2016

#18a^2-51a+21#

Explanation:

We must ensure that each term in the second bracket is multiplied by each term in the first bracket.
This can be done as follows.

#(color(red)(-3a+7))(-6a+3)#

#=color(red)(-3a)(-6a+3)color(red)(+7)(-6a+3)#

distribute the brackets.

#=18a^2-9a-42a+21#

collect like terms.

#=18a^2-51a+21#