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Exercises Numbers, fractions and percents

Example 4.80 from Prealgebra, 4.5 Add and Subtract Fractions with Different Denominators

Add and Subtract Fractions with Different Denominators: example 4.80

Evaluate $\frac{p + q}{r}$ when $p = −4, q = −2,$ and $r = 8 .$

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
We substitute the values into the expression and simplify.

$\frac{p + q}{r}$

Add in the numerator first. $- \frac{6}{8}$

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

Your turn

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

Evaluate: $\frac{a + b}{c}$ when $a = −8, b = −7, and c = 6 .$

How did it go?

PreviousAdd and Subtract Fractions with Different Denominators: example 4.79 Next Add and Subtract Mixed Numbers: example 4.81

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.