Show that the points `(a+5,a-4),(a-2,a+3)` and `(a,a)` do not lie on a straight line of any value of `a`.

Explanation

Given the points are `(a+5,a-4),(a-2,a+3)` and `(a,a)`
`:. Delta=1/2|(a+5,a-4,1),(a-2,a+3,1),(a,a,1)|`
`=1/2|(5,-4,0),(-2,3,0),(a,a,1)|[ :' R_(1)toR_(1)-R_(3)` and `R_(2)toR_(2)-R_(3)]`
`=1/2[1(15-8)]`
`implies7/2!=0`
Hence given points form a triangle i.e., points do not lie in a straight line.