SOLUTION: Solving Systems Using Elimination. Your math test has 38 questions and is worth 200 points. The test consist of multiple choice questions worth 4 points each and open ended questio

Your start is fine.


The next steps are

     x +  y =   38    (1)
    4x + 20y = 200    (2)


To solve by Elimination, multiply equation (1) by 4 (both sides). Keep equation (2) as is.


    4x + 4y =  4*38   (1')
    4x + 20y = 200    (2')


Now subtract equation (1') from equation (2').  The terms " 4x " will kill each other, and you will get single equation 
for variable "y" only (!)


         20y - 4y = 200 - 4*38 

         16y      = 48

           y      = 48/16 = 3.


It how the Elimination method works.


Finally, substitute the value y= 3 into equation (1) to get "x".


          x + 3 = 38

          x     = 38-3 = 35.


ANSWER.  x= 35;  y= 3.