Final answer:
The correct value of n for which the distance between the points P(3n, n-7) and Q(4n, n+5) is 13 units is n = 5.
Step-by-step explanation:
The student is asked to determine the value(s) of n for which the distance between the points P(3n, n-7) and Q(4n, n+5) is 13 units. To find this, we apply the distance formula between the two points:
Distance, PQ = \(\sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}\)
Plugging in the coordinates of P and Q, we get:
13 = \(\sqrt{(4n - 3n)^2 + ((n + 5) - (n - 7))^2}\)
Simplifying the equation:
13 = \(\sqrt{n^2 + 12^2}\)
13 = \(\sqrt{n^2 + 144}\)
Squaring both sides gives:
169 = n^2 + 144
n^2 = 169 - 144
n^2 = 25
n = \(\pm\sqrt{25}\)
n = \(\pm5\)
However, since n represents a coordinate, we consider only the positive value, thus n = 5.