A line intersects the y-axis and x-axis at points P and Q respectively. If (2, -5) is the mid point of PQ, then find the coordinates of P and Q.

Let the coordinates of P be (x₁, y₁) and Q be (x₂, y₂).
Midpoint of PQ = (2, -5)
By midpoint formula,
x = (x₁ + x₂)/2 and y = (y₁ + y₂)/2
2 = (x₁ + x₂)/2 and -5 = (y₁ + y₂)/2
∴ x₁ + x₂ = 4 and y₁ + y₂ = -10
Since line PQ intersects the y-axis at P, so x₁ = 0.
Similarly, y₂ = 0
∴ x₂ = 4 and y₁ = -10
The coordinates of P are (0, -10) and Q are (4, 0).