Subtracting Fractions

• 
  

  1	–	1	=
  3		6

  
  

• 
  

  STEP 1: Subtract the fractions.

  ---

  
  

  Both fractions have different denominators and thus are unable to be easily subtracted together. Find the least common multiple (LCM) of the denominators.

  
  

• 
  

  STEP 2: Change the unlike denominators to like denominators.

  ---

  
  

  The LCM is the same as the LCD (Least Common Denominator). Multiply both the numerator and the denominator by the LCD so that the fractions will have like denominators. If a fraction's denominator is already the LCD, then it does not need to be converted.

  
  

• 
  

  STEP 3: Simplify and subtract.

  ---

  
  

  Convert the fraction to have like denominators. Then subtract.