SOLUTION: <pre> I need the answer and need to know how you got the answer for a solving systems using elimination. 7x + 2y = 10 -7x + y = -16</pre>

Algebra ->  Coordinate Systems and Linear Equations -> SOLUTION: <pre> I need the answer and need to know how you got the answer for a solving systems using elimination. 7x + 2y = 10 -7x + y = -16</pre>      Log On


   

Question 371480: 
I need the answer and need to know how you got the answer for a solving systems
using elimination.   7x + 2y =  10
                    -7x +  y = -16
Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
Add corresponding terms of the two equations and the x-terms
will cancel out automatically since one is 7x and the other is -7x:

 7x + 2y =  10
-7x +  y = -16
--------------
      3y =  -6
      3y%2F3 = -6%2F3
       y =  -2


Substitute -2 for y in either equation:

    7x + 2y = 10
 7x + 2(-2) = 10
     7x - 4 = 10
         +4   +4
    ------------
     2x     = 14
         2x%2F2 = 14%2F2
          x = 7 
          
Edwin