SOLUTION: When adding and subtracting rational numbers (fractions), why does one need a common denominator? For what reason is it recommended that one use the lowest common denominator (lcd

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: When adding and subtracting rational numbers (fractions), why does one need a common denominator? For what reason is it recommended that one use the lowest common denominator (lcd      Log On


   

Question 316986: When adding and subtracting rational numbers (fractions), why does one need a common denominator? For what reason is it recommended that one use the lowest common denominator (lcd)?
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
1/3+1/6+2/12
The LCD is 12.
(4+2+2*1)/12=(6+2)/12=8/12=2/3 ans.
Now use 36 which is also a common denominator.
(12+6+2*3)/36=(18+6)/36=24/36=12/18=6/9=2/3 this larger common denominator requires you to work with larger numbers and requires more fraction reductions.