Question

if the points A(X, Y) B(3,6) AND (-3,4) ARE COLLINEAR, Show THAT X-3Y+15=0

Answer 1

Answer:

a lies in the 1st quadrant (+,+) ; B lies in the second quadrant (- , +) ;

∴ X - 3Y + 15 = 0

X = 3 AND -3

Y = 6 AND 4

IN THE 1ST CASE :

 3 - 3×6 +15 = 0

3 - 18 + 15 = 0

18-18 = 0

IN THE 2ND CASE :

 - 3 - 3 × 4 +15 = 0

-3 -12+15=0

-15+15=0

THEREFORE, X-3Y+15=0

Answer 2

Since they are collinear slope of BC=AC

(6-4)/(3- -3)=(y-4)/(x- -3)

2/6=(y-4)/(x+3)

x+3=3y-12

x-3y+15=0