How can Newton's first law be derived from Newton's second law?

1st Law states that an object will continue without a change in motion (constant velocity) if there are no outside forces.

2nd Law states that to have an , there must be an outside force. ##sumF=m*a##

If F = 0

##sumF=m*a## becomes ##0=m*a## ##0=a##

And if there is no acceleration, there is no change in motion (1st law).