Which ordered pair in the form (x, y) is a solution of this equation?

(x + 6) y = 9

4, 1)

(2, 1)

(3, 1)

(12, 2)

(3, 1)

substitute each ordered pair into the left side of the equation and if equal to the right side then it is a solution

(4, 1)

(4 + 6) * 1 = 10 * 1 = 10 ≠ 9 ← not a solution

(2, 1)

(2 + 6) * 1 = 8 * 1 = 8 ≠ 9 ← not a solution

(3, 1)

(3 + 6) * 1 = 9 * 1 = 9 ← hence a solution

(12, 2)

(12 + 6) * 2 = 18 * 2 = 36 ≠ 9 ← not a solution