Explanation:
you made so many typos.
let's see :
the point-slope form of a line is
y - y1 = a(x - x1)
"a" being the slope, (x1, y1) being a point on the line.
in our case
y - -16 = 1/2 × (x - 16)
y + 16 = x/2 - 16/2 = x/2 - 8
y = x/2 - 24
or
y = (1/2)x - 24