Question 64980
Find the sum or difference. - 11/12 - -7/15  First off, lets rewrite it noting that (-)(-)=(+):

-11/12--7/15=

-11/12+7/15   Next we'll multiply both terms by 60/60.  (60 is the lowest common multiple (LCM) of 12 & 15).  We are doing this in order to get a common denominator for both terms.  When we get a common denomator, we can start simplifying the resulting fraction.


(-11/12)(60/60)+(7/15)(60/60)=

((-11)(5))/60+((7)(4))/60 simplifying we have:

(-55+28)/60=
-27/60  reducing the fraction we get
((-3)(9))/((3)(20))=

-9/20

Hope this helps.  Happy holidays----ptaylor