What is meant by "simplest form" or "lowest terms"?

A fraction is in simplest form (lowest terms) when the numerator and denominator have no common factors other than 1.

Examples:

• 2/3 is in simplest form (GCD = 1)
• 8/12 is NOT in simplest form (GCD = 4), simplifies to 2/3
• 15/20 is NOT in simplest form (GCD = 5), simplifies to 3/4

Same as standard form: When denominator is also positive.

Addition and Subtraction (Questions 21-30)

21. How do you add two rational numbers with the same denominator?

When denominators are the same, add the numerators and keep the denominator.

Formula: p/q + r/q = (p + r)/q

Example:

3/7 + 2/7 = (3 + 2)/7 = 5/7

Another Example:

-5/9 + 2/9 = (-5 + 2)/9 = -3/9 = -1/3