Name: ___________________

Date:___________________

kwizNET Subscribers, please login to turn off the Ads!
Email us to get an instant 20% discount on highly effective K-12 Math & English kwizNET Programs!

Grade 8 - Mathematics
7.45 Problems - IX

Example:
If x+1/x = 3, find the value of x3+1/x3.
Solution:
Given that,
x+1/x = 3
Cubing on both sides, we get
(x+1/x)3 = 33
x3+1/x3+3.x.1/x.(x+1/x) = 27
x3+1/x3+3.3 = 27
x3+1/x3+9 = 27
x3+1/x3 = 27-9
x3+1/x3 = 18


Directions: Solve the following problems.
Q 1: If x+1/x = 6, find the value of x3+1/x3.
198
192
196
194

Q 2: If x+1/x = 10, find the value of x3+1/x3.
965
970
975
960

Q 3: If x+1/x = 8, find the value of x3+1/x3.
488
484
486
482

Q 4: If x+1/x = 5, find the value of x3+1/x3.
117
115
119
113

Q 5: If x+1/x = 4, find the value of x3+1/x3.
56
58
54
52

Q 6: If x+1/x = 7, find the value of x3+1/x3.
326
324
322
328

Question 7: This question is available to subscribers only!

Question 8: This question is available to subscribers only!


Subscription to kwizNET Learning System costs less than $1 per month & offers the following benefits:

  • Unrestricted access to grade appropriate lessons, quizzes, & printable worksheets
  • Instant scoring of online quizzes
  • Progress tracking and award certificates to keep your student motivated
  • Unlimited practice with auto-generated 'WIZ MATH' quizzes
  • Child-friendly website with no advertisements


© 2003-2007 kwizNET Learning System LLC. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. For permission, contact info@kwizNET.com
For unlimited printable worksheets & more, go to http://www.kwizNET.com.