Question

Determaine the equation of the line containing each pair of points. Express your answers in the form: i) ax+by+c=0 and ii) y=mx+c:

1,1) (5,5)

Answer 1

For the y = mx + b form,

slope = m = (5-1)/(5-1) = 1

5 = mx + c = 1*5 + c
c = 0

y = x

That can be easily changed to the ax + bx + c = 0 form. Actually there are an infinite number of ways writing it in ax + by + c = 0 form. Just multiply all terms by any constant.