x + 2y and 2x + 4y are linear combinations of each other since 2 ( x + 2y ) = 2x + 4y.
However, since 2 ( x + 2y = 2 ) results in 2x + 4y = 4 and the second equation reads as 2x + 4y = -8, there is no solution to this system of equations since 4 does not equal -8.