Systems
Both equations are solved for "y". Let's take one of them and plug it into the other one. I'll plug 2x + 4 instead of y in the second equation, y = 2x - 6.
y = 2x - 6
2x + 4 = 2x - 6
2x - 2x = -6 - 4
0x = -10
0 = -10
Since the statement is false, this system has no solutions.