we can write the equation in this way also:
4x-4=16
taking (-4) to opposite side,
since it has (-) sign , it becomes (+) when we take it to the opposite side
now the equation becomes
4x=16+4
i.e.
4x=20
now, we take 4 to the opposite side
the equation becomes
x=20/4
i.e. x=5
so the answer is
c.5
