Question 305695
First switch it around so that all the variables are on one side and the numbers are on the other:
2x+4y=14
4x+5y=31

Then you want to get one variable out of the equation (this is where the addition method comes nto play). Lets get rid of X since it's easiest to do. You have to multiply one of the equations so that the Xs cancel out and you are left with only a Y:
-2(2x+4y=14) -->>     -4x-8y=-28

Add the equations:   + 4x+5y= 31
                     
                          3y= 3

Solve:                     y= 1

Put the answer to Y into one of the original equations and you'll find the answer:
        -2x=4(1)-14
        -2x=4-14
        -2x=-10
          x=5

Answer: (5,1)
Hope this helped you man. Enjoy :)