The system of linear equations with one solution. Examples: {x+1=3; y+2=4}, {x=3; x+y=5}, {x+y=3; x-y=1}. The system of linear equations with infinite solutions. Examples: {x+y=1; x+y=1}, {2x+y=3; 2x+y=3}, {x=x; y=y}. Then system of linear equations with zero solutions. Examples: {x+y=1; x+y=2}, {2x+y=3; 2x+y=5}, {x+1=x, x+y=3}.