Answer: n = -4
because the line (d) passes through (6;3) and (8;4)
=> (d): passes through (6;3)
the normal vector n(1; -2)
=> (d): x - 6 - 2(y - 3) = 0
=> (d): x - 2y = 0
because d also passes through (n; -2)
=> n - 2.(-2) = 0
⇔ n + 4 = 0
⇔ n = -4
Step-by-step explanation:
