+0  
 
+1
83
1
avatar+66 

Lisa solved  3x2 + 1 = 28  as shown:

3x2 + 1 = 28 

3x2  = 27

   x2  = 9

 

She concluded that the solutions are x = -9   or   x = 9. 

 

1.  Using complete sentences, explain what mistake she made.

 

2.  What are the correct solutions?  

skye25  Sep 25, 2018
 #1
avatar+92505 
+1

The mistake is that she forgot to take both square roots  of   9   =   3  or  -3

 

 

 

cool cool cool

CPhill  Sep 25, 2018

9 Online Users

avatar

New Privacy Policy

We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive information about your use of our website.
For more information: our cookie policy and privacy policy.