Question 289999
1.{{{3x-7y=1}}}
2.{{{6x=14y+2}}}
2.{{{6x-14y=2}}}
Multiply eq. 1 by -2 and add to eq. 2 to eliminate y.
{{{-6x+14y+6x-14y=-2+2}}}
{{{0=0}}}
Eq. 1 and eq. 2 are the same line. 
They have an infinite number of solutions.