Step-by-step explanation:
[tex]y = 2x - 4[/tex]
[tex]3x + y = 1[/tex]
[tex]y = 1 - 3x[/tex]
Equating,
[tex]2x - 4 = 1 - 3x[/tex]
[tex]2x + 3x = 1 + 4[/tex]
[tex]5x = 5[/tex]
[tex]x = 1[/tex]
Placing it,
[tex]y = 1 - 3( 1)[/tex]
[tex]y = 1 - 3[/tex]
[tex]y = - 2[/tex]