Find the ratio in which the x -axis divides the line segment joining the points(3, -2) and (-7, -1).

SOLUTION:

Any point on the x –axis will be of the form A(x, 0). Let this point divides the line segment joining (3, -2) and (-7, -1) in the ratio
m: n internally.

Thus the coordinate of A is
here the y coordinate of A is zero.

⇒ –m – 2n = 0

⇒ –m = 2n
∴ The required ratio is 2: -1
⇒ m : n = 2 : -1 internally
Thus m : n = 2 : 1 externally.