Name: Roger Hornbaker
Who is asking: Student
Level: All

I am having problem figuring out x and y solutions.

  1. 5x + y = 4
    3x - y = 4

  2.   3x + 2y = 6
    - 3x +  y = 0
Hi Roger,

These equations are set up to make them easy for you to solve. Notice, for example in the first pair of equations the coefficient of y in the first equation is +1 and the coefficient of y in the second equation is -1. If you add the two equations you get

5x + 3x + y - y = 4 + 4

whic simplifies to

8x = 8

(The fact that the coefficioents of y are +1 and -1 made them cancel out when the equations were added.)


8x = 8,

dividing both sides by 8 gives x = 1. Now you can substitute x = 1 into either of the equations you started with to find y.
   Now try the second pair of equations.


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