Answer:
[tex]y = 2x + 1 \\ substitute \: for \: y \: in \: x + y = 7 \\ x + (2x + 1) = 7 \\ 3x = - 6 \\ x = - \frac{1}{2} \\ y = 2( - \frac{1}{2} ) + 1 \\ y = - 1 + 1 \\ y = 0[/tex]
