How do you evaluate #3( - 4) + 6( - 1)#?

1 Answer
Mar 2, 2018

A positive times a negative is a positive, and adding a negative is the same as subtracting.

Explanation:

#3(-4)+6(-1)#
Because a negative times a positive is a negative, we get
#-12+##-6#
And because adding a negative is the same as subtracting we get
#-12-6#, which is equal to #-18#
A less confusing way to add a negative to a negative is to treat it like this
#-a+##-b=-(a+b)#
This means we can work out #a+b# and then just put a negative sign on the front.