+0  
 
0
140
4
avatar

6*(x-5)-2*(4x+2) ≥ 80, in the numeric set Z (sorry if not right), the result i got was x ≥ -57, it should be write {-57,-58,-59,...} or {...,-59, -58, -57}? And why?  

Guest Jul 9, 2017
Sort: 

4+0 Answers

 #1
avatar+79843 
+1

 

Actually, the solution  is

 

x ≤ - 57

 

You can write your solution as

 

( - ∞ , -57 ]      

 

The bracket shows that the number to its left is included in the solution...infinities are never bracketed but are shown with a parentheses beside them

 

 

 

cool cool cool

CPhill  Jul 9, 2017
 #2
avatar
0

thanks, but could you write the process to the result for me? im more confused than a blind man in a shooting.

Guest Jul 9, 2017
 #3
avatar+79843 
+1

 

6*(x-5)-2*(4x+2) ≥ 80     simplify

 

6x - 30 - 8x - 4  ≥ 80      combine like terms on the left

 

-2x - 34  ≥ 80      add 34 to both sides

 

-2x  ≥  114          

 

divide both sides by -2......don't forget to reverse the inequality sign as we do in an inequality when we  divide or multiply by a negative  !!!

 

x ≤ - 57

 

 

cool cool cool

CPhill  Jul 10, 2017
edited by CPhill  Jul 10, 2017
 #4
avatar
0

Thank you very much man, you answered my two questions on this site and even explained it, man you helped me a lot, thank you very much, really, thank you.

Guest Jul 10, 2017

19 Online Users

We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.  See details