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Exercises Equations and inequalities

Example 2.36 from Elementary Algebra, 2.3 Solve Equations with Variables and Constants on Both Sides

Solve Equations with Variables and Constants on Both Sides: example 2.36

Solve: $7.8 x + 4 = 5.4 x - 8 .$

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
Since $7.8 > 5.4$ , make the left side the “variable” side and the right side the “constant” side.

Subtract $5.4 x$ from both sides.

Combine like terms.

Subtract $4$ from both sides.

Simplify.

Use the Division Propery of Equality.

Simplify.

Check:

Let $x = −5$ .

Your turn

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

Solve: $2.8 x + 12 = −1.4 x - 9 .$

How did it go?

PreviousSolve Equations with Variables and Constants on Both Sides: example 2.35 Next Use a General Strategy to Solve Linear Equations: example 2.37

From Elementary Algebra (1st edition) by OpenStax (Rice University), section 2.3, 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.