We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. cookie policy and privacy policy.
 
+0  
 
0
308
1
avatar+4116 

Help.

 Oct 10, 2017
 #1
avatar+100587 
+1

 

5x + 4y  =  12     (1)

3x - 3y   =  18      divide through by 3  →  x - y  =  6  ..... 

multiply through by 4 →  4x - 4y  = 24      (2)

 

Add (1)  and (2)

 

9x  =  36       divide through by 9

 

x  = 4

 

Using    x - y  =   6, we have

 

4 - y  = 6        add y to both sides, subtract 6 from both sides

 

4 - 6  = y  =  -2

 

 

cool cool cool

 Oct 10, 2017
edited by CPhill  Oct 10, 2017

4 Online Users