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Exercises Numbers, fractions and percents

Example 4.103 from Prealgebra, 4.7 Solve Equations with Fractions

Solve Equations with Fractions: example 4.103

Solve: $- \frac{3}{8} w = 72 .$

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 coefficient is a negative fraction. Remember that a number and its reciprocal have the same sign, so the reciprocal of the coefficient must also be negative.

Multiply both sides by the reciprocal of $− \frac{3}{8}$ .

Simplify; reciprocals multiply to one.

Multiply.

Check:

Let $w = −192$ .

Multiply. It checks.

Your turn

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

Solve: $- \frac{4}{7} a = 52 .$

How did it go?

PreviousSolve Equations with Fractions: example 4.102 Next Solve Equations with Fractions: example 4.104

From Prealgebra (1st edition) by OpenStax (Rice University), section 4.7, 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.