As points (a, 0) , (x , y) and (0, b) are collinear
∴ a (y − b) + x (b − 0) + 0 (0 − y) = 0,
⇒ ay − ab + xb = 0,
⇒ xb + ay + ab.
Divide both side by ‘ab’ we get
x / a + y / b = 1.
Abscissa is 3 on negative side of x-axis. Hence x-coordinate = −3.
Ordinates 5 on the positive side of y-axis. Hence y –coordinate = 5.
Co-ordinate of point are ( − 3, 5)