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Exercises Numbers, fractions and percents

Example 4.68 from Prealgebra, 4.5 Add and Subtract Fractions with Different Denominators

Add and Subtract Fractions with Different Denominators: example 4.68

Subtract: $\frac{1}{2} - (- \frac{1}{4}) .$

Work it out on paper first. Then open the solution one step at a time, and stop as soon as you can finish on your own.

Solution

$\frac{1}{2} - (- \frac{1}{4})$

Find the LCD of 2 and 4.

Rewrite as equivalent fractions using the LCD 4.

Simplify the first fraction. $\frac{2}{4} - (- \frac{1}{4})$

Subtract. $\frac{2 - (−1)}{4}$

Simplify. $\frac{3}{4}$

One of the fractions already had the least common denominator, so we only had to convert the other fraction.

Your turn

The book's Try It right after this example: same idea, new numbers. Only the answer is given.

Simplify: $\frac{1}{2} - (- \frac{1}{8}) .$

How did it go?

PreviousAdd and Subtract Fractions with Different Denominators: example 4.67 Next Add and Subtract Fractions with Different Denominators: example 4.69

From Prealgebra (1st edition) by OpenStax (Rice University), section 4.5, licensed under CC BY 4.0. Original at openstax.org. We split the solution into steps; the words, numbers and figures are the book's. OpenStax doesn't endorse this site.