G S Rehill's Interactive Maths Software Series - "Building a Strong Foundation in Mathematics" from mathsteacher.com.au.

Order a 12-month Year 7 Interactive Maths software Homework Licence for only $19.95. Order a 12-month Year 8 Interactive Maths software Homework Licence for only $19.95. Order a 12-month Year 9 Interactive Maths software Homework Licence for only $19.95. Order a 12-month Year 10 Interactive Maths software Homework Licence for only $19.95.

Year 10 Interactive Maths - Second Edition


Dividing Each Side of an Inequality by a Negative Number

If each side of an inequality is divided by the same negative number, then:

>= becomes <=, > becomes <, <= becomes >=, < becomes >


Example 28

Solve the inequality -7x > 98 for x.

Solution:

Divide both sides by -7 and change > into < to find x < -14.

Therefore, the solution set is {x : x < -14}.


Example 29

Solve the inequality -12x <=4 for x.

Solution:

Divide both sides by -12 and change <= into >= to find x >= - 1 / 3. Therefore, the solution set is {x : x >= - 1 / 3}.


Just to recap the foregoing discussion:
  • The same number can be added to both sides of an inequality.
  • The same number can be subtracted from both sides of an inequality.
  • Both sides of an inequality can be multiplied or divided by the same positive number.
  • If an inequality is multiplied (or divided) by a negative number, then:

>= becomes <=, > becomes <, <= becomes >=, < becomes >


| Home Page | Order Maths Software | About the Series | Maths Software Tutorials |
| Year 7 Maths Software | Year 8 Maths Software | Year 9 Maths Software | Year 10 Maths Software |
| Homework Software | Tutor Software | Maths Software Platform | Trial Maths Software |
| Feedback | About mathsteacher.com.au | Terms and Conditions | Our Policies | Links | Contact |

Copyright © 2000-2022 mathsteacher.com Pty Ltd.  All rights reserved.
Australian Business Number 53 056 217 611

Copyright instructions for educational institutions

Please read the Terms and Conditions of Use of this Website and our Privacy and Other Policies.
If you experience difficulties when using this Website, tell us through the feedback form or by phoning the contact telephone number.