Flashcard 7 - Mathematics Flashcard Set for the HESI Exam

For fractions with a common denominator: Add or subtract the numerators as usual while keeping the denominator.

For fractions with unlike denominators:
Determine the least common denominator (LCD).
Convert the first fraction to an equivalent fraction with the LCD as its denominator.
Do the same with the second fraction.
Add the two fractions as you would with fractions with a common denominator.

Subtraction will follow the same procedures except that you use subtraction or “minus.”

\[\frac{2}{3} + \frac{5}{7}\]

The LCD of the 2 fractions is 21.

Converting to equivalent fractions:

\(\frac{2}{3} = \frac{14}{21}\) and \(\frac{5}{7} = \frac{15}{21}\)

Proceeding to addition:

\[\frac{14}{21} + \frac{15}{21} = \frac{29}{21}\]