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Exercises Numbers, fractions and percents

Example 4.72 from Prealgebra, 4.5 Add and Subtract Fractions with Different Denominators

Add and Subtract Fractions with Different Denominators: example 4.72

Add: $\frac{3}{5} + \frac{x}{8} .$

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
The fractions have different denominators.

$\frac{3}{5} + \frac{x}{8}$

Find the LCD.

Rewrite as equivalent fractions with the LCD.

Simplify the numerators and denominators. $\frac{24}{40} + \frac{5 x}{40}$

Add. $\frac{24 + 5 x}{40}$

We cannot add $24$ and $5 x$ since they are not like terms, so we cannot simplify the expression any further.

Your turn

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

Add: $\frac{y}{6} + \frac{7}{9} .$

How did it go?

PreviousAdd and Subtract Fractions with Different Denominators: example 4.71 Next Add and Subtract Fractions with Different Denominators: example 4.73

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.