Solution:
Since the graph passes through the given points, (7, 20) & (-2, 11) are the solutions of the given equation y = x + ?.
⇒(x, y) = (7, 20); (-2, 11)
Substituting the variables with (7, 20),
20 = 7 + ?
20 - 7 = ?
? = 13
Similarly,
11 = -2 + ?
? = 13
∴ y = 13
