The ab segment equation is
X=-3 where -1≤y≤6
Point b lies on line X+Y=0
The point of intersecton is x=-3 ,y=3
The line segment is divided into two parts and its length is measured on Y axis
First part of divided segment =3-(-1)=4
Second part of divided segment =6-3=3
Point p divides the line 3:4 =3/4 :1