How do you evaluate #-\frac { 3} { 10} + ( - \frac { 9} { 10} )#?

1 Answer
Jun 14, 2017

#-12/10# or #-1 2/10#

Explanation:

#-3/10+(-9/10)#

We first open the brackets. When we do that, remember that the product of one minus and one plus results in a minus.

#-3/10-9/10#

Now, to make things easier, we put both terms within one set of brackets, but keep the minus sign out. That will make both terms inside positive.

#-(3/10+9/10)#

Since both the terms inside the brackets have the same denominator, the numerators can be added directly.

#-((3+9)/10)#

#-(12/10)#

Once again, we open the brackets, keeping in mind that the product of a minus and a plus is a minus.

#-12/10#

We can now make this into a mixed fraction. #10# goes into #12# once, leaving #2# as remainder.

#-1 2/10#