Which system of equations has no solution?
{x+2y=52x+4y=10\begin{cases} x + 2y = 5 \\ 2x + 4y = 10 \end{cases}{x+2y=52x+4y=10
{x−y=22x−2y=4\begin{cases} x - y = 2 \\ 2x - 2y = 4 \end{cases}{x−y=22x−2y=4
{x+y=3x+y=5\begin{cases} x + y = 3 \\ x + y = 5 \end{cases}{x+y=3x+y=5
{3x+2y=7x−y=1\begin{cases} 3x + 2y = 7 \\ x - y = 1 \end{cases}{3x+2y=7x−y=1