Finding the LCM

1
Finding the LCM

• Rule 6-1
• To find the lowest common multiple of numbers
  containing literal numbers
• factor each term
• determine the maximum number of times a prime
  factor appears in any one term
• multiply the resulting prime factors found in
  step 2. This number is the LCM.

2
Multiplication with Literal Numbers

• Key Point
• In multiplication, all the literal numbers
  contained in the multiplicand and the multiplier
  must appear in the product unless the exponent is
  zero.

3
Multiplying Fractions

• Key Point
• To multiply fractions, we
• Cancel factors that are common to both numerators
  and denominators.
• Multiply the remaining numerators (their product
  is the numerator of the answer).
• Multiply the remaining denominators (their
  product is the denominator of the answer).

4
Adding and Subtracting Fractions

• Rule 6-2
• To add (or subtract) fractions with unlike
  denominators
• find the CD.
• Change the denominator of all fractions to this
  denominator.
• Divide the CD by the old denominator of each
  fraction

5
Adding and Subtracting Fractions (cont.)

• Then multiply this number by the old numerator to
  find the new numerator of the fraction.
• Add (or subtract) the fractions, combining all
  like terms in the numerator.
• Reduce the answer to the lowest terms.