Finding the LCM Rule 6 ‑ 1: To find the lowest common multiple of numbers containing literal numbers: 1. factor each term; 2. determine the maximum number of times a prime factor appears in any one term; 3. multiply the resulting prime factors found in step 2. This number is the LCM.

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.

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).

Adding and Subtracting Fractions Rule 6 ‑ 2: To add (or subtract) fractions with unlike denominators: 1. find the CD. 2. Change the denominator of all fractions to this denominator. 3. Divide the CD by the old denominator of each fraction

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.