+0  
 
0
320
1
avatar

 If $x + y =2$ and $xy = 23$, then what is $x^2 + y^2$?

 Sep 28, 2017
 #1
avatar+98090 
+2

 If $x + y =2$ and $xy = 23$, then what is $x^2 + y^2$?

 

x + y  = 2    square both sides

 

x^2 + 2xy + y^2  =  4

 

x^2 + 2(23) + y^2  = 4

 

x^2 + 46  +  y^2   =  4     subtract 46 from both sides

 

x^2  + y^2  =  -44

 

 

cool cool cool

 Sep 29, 2017

27 Online Users

avatar
avatar
avatar
avatar