/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 4 Solve each polynomial inequality... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Solve each polynomial inequality and graph the solution set on a real number line. Express each solution set in interval notation. $$(x+1)(x-7) \leq 0$$

Short Answer

Expert verified
The solution to the inequality \((x+1)(x-7) \leq 0\) is \([-1,7]\) in interval notation.

Step by step solution

01

Find the Roots

The roots of the inequality \((x+1)(x-7) \leq 0\) are found by setting each factor equal to zero. Those factors are \(x+1\) and \(x-7\). Solving \(x+1=0\) gives \(x=-1\) and solving \(x-7=0\) gives \(x=7\).
02

Determine the Test Intervals

With these roots, the number line can be divided into three intervals. These intervals are \((-∞,-1)\), \((-1,7)\), and \((7,∞)\).
03

Test the Intervals

Choose a test value from each interval and substitute it into the inequality to see if it makes the inequality true. For \((-∞,-1)\), let's choose \(x=-2\). Then \((-2+1)(-2-7) = 9\) which is more than 0, so this interval does not satisfy the inequality. For \((-1,7)\), let's choose \(x=0\). Then \((0+1)(0-7) = -7\) which is less than or equal to zero, so this interval satisfies the inequality. For \((7,∞)\), let’s choose \(x=8\). Then \((8+1)(8-7) = 8\), which is more than 0 so this interval also does not satisfy the inequality.
04

Write the Solution in Interval Notation

In interval notation, the solution set of the inequality \((x+1)(x-7) \leq 0\) is \([-1,7]\), including the endpoints -1 and 7 since the original inequality allows for equality (≤ rather than <).

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Study anywhere. Anytime. Across all devices.