y = x + 1....so we sub in x + 1 for y in the other equation
2x + y = 7
2x + x + 1 = 7 ....combine like terms
3x + 1 = 7....subtract 1 from both sides
3x = 7 - 1
3x = 6 ....divide both sides by 3
x = 6/3
x = 2
y = x + 1
y = 2 + 1
y = 3
so ur solution is : (2,3)