Very arty photograph with the hands reflecting. I like it.
I prefer point point form, the line through (a,b) and (c,d) is
(c - a)(y - b) = (d - b)(x - a)
This is really the same as point slope form, without the awkward possibility of divsion by zero,
y - b = m (x -a ) where m = (d - b) / (c - a)
Join of (-1, 6) and (1,-4)
m = (-4 - 6)/(1 - -1) = -10/2 = -5
y - 6 = -5(x - -1)
Answer: y = -5x + 1
check: -5(-1)+1=5+1=6, good, -5(1)+1=-5+1=-4, good