Question 773557
(3,5) and (9,7)
leads to

{{{m=(y[2]-y[1]  )/(x[2]-x[1]  )=(7-5)/(9-3)=1/3
}}}


Then
using  (3,5)
{{{
y-y[0] = m(x-x[0])
}}}
becomes
{{{
y-5 = (1/3)(x-3)
}}}