Answer:
x + 3y = 7
Explanation:
The equation of a line which passes through (x₁, y₁) and with slope of m in point-slope form:
y - y₁ = m(x - x₁)
m = -¹/₃
(1, 2) ⇒ x₁ = 1, y₁ = 2
Therefore, the equation of the line which passes through (1, 2) and with slope of −1/3 in point-slope form:
y - 2 = -¹/₃(x - 1)
y - 2 = -¹/₃x + ¹/₃ {add ¹/₃x to both sides}
¹/₃x + y - 2 = ¹/₃ {add 2 to both sides}
¹/₃x + y = 2¹/₃ {multiply both sides by 3}
x + 3y = 7