Respuesta :

2x + y = 7
2x +x + 1 = 7
3x + 1 = 7

answer : 3x + 1 = 7
y = x+1

When the expression x+1 is substituted in for y in the first equation
2x + y = 7
⇒ 2x + (x+1) = 7
⇒ 2x + x + 1 = 7
⇒ 3x + 1 = 7

Hope it helps!