Example

Example: Solving and Graphing 3(2x+5)183(2x+5) \leq 18 and 2(x7)<62(x-7) < -6

To solve the compound inequality 3(2x+5)183(2x+5) \leq 18 and 2(x7)<62(x-7) < -6, start by simplifying both sides of each inequality. For the first inequality, expanding the left side gives 6x+15186x + 15 \leq 18. Subtracting 1515 yields 6x36x \leq 3, which simplifies to x12x \leq \frac{1}{2}. For the second inequality, expanding gives 2x14<62x - 14 < -6. Adding 1414 results in 2x<82x < 8, which simplifies to x<4x < 4. Graphing each solution shows that the values satisfying both conditions must be in the overlap. The graph of x12x \leq \frac{1}{2} is shaded to the left with a right bracket at 12\frac{1}{2}, and x<4x < 4 is shaded to the left with a right parenthesis at 44. The intersection of these two graphs is simply the region where x12x \leq \frac{1}{2}, because any number less than or equal to 12\frac{1}{2} is also automatically less than 44. In interval notation, this final combined solution is written as (,12](-\infty, \frac{1}{2}].

Image 0

0

1

Updated 2026-05-02

Contributors are:

Who are from:

Tags

OpenStax

Intermediate Algebra @ OpenStax

Ch.2 Solving Linear Equations - Intermediate Algebra @ OpenStax

Algebra