Hard

x+2x=12

3x=12

x=4

To solve this you are given   y= 2x     Substitiute this value of y in to the second equation...

     x + 2x = 12

    3x = 12

      x = 4         Now that you know x....you can substitute this into any of the equations to find y

        the simplest is  y = 2x    so y = 2(4) = 8        so x,y =  4,8