Question

if the points A(x,y), B(a,0), C(a,b) are collinear. prove that, x/a+y/b=1

Answer 1

use area of triangle form by three points equal to zero

so,
area of triangle=1/2 {x (0-b)+a (b-y)+0}
0=-bx +ab-ay
ay+bx=ab
divided both side ab
y/b+x/a=1
hence
x/a+y/b=1