This is in point slope form.
Basically, point-slope form is:
y -
= m(x -
)
With
and
being points on the line.
So therefore, in this equation, you see 5 and 1 in those places.
However, since you're subtracting
and
, and in the equation you seem to be adding 5 and adding 1, this means that the points must be -5 and -1 for it to work.
So therefore:
(-1, -5) is a solution of the equation y + 5 = 2(x + 1)