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Exercises Equations and inequalities

Example 1 from Algebra and Trigonometry, 2.2 Linear Equations in One Variable

Solving an Equation in One Variable

Solve the following equation: $2 x + 7 = 19.$

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
This equation can be written in the form $a x + b = 0$ by subtracting $19$ from both sides. However, we may proceed to solve the equation in its original form by performing algebraic operations.

$\begin{matrix} 2 x + 7 & = & 19 \\ 2 x & = & 12 & Subtract 7 from both sides . \\ x & = & 6 & Multiply both sides by \frac{1}{2} or divide by 2 . \end{matrix}$
The solution is 6.

Your turn

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

Solve the linear equation in one variable: $2 x + 1 = −9.$

How did it go?

PreviousFinding the Center of a Circle Next Solving an Equation Algebraically When the Variable Appears on Both Sides

From Algebra and Trigonometry (1st edition) by OpenStax (Rice University), section 2.2, 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.