At about the 0:34 mark, the teacher says our goal is to get it into...standard form; he should have said get it into vertex form.
At about the 4:42 mark, the teacher writes ±sqrt(5)=x+2; he should have written ±sqrt(5)=x-2. Because of this, he also gets the wrong zeros; he should get x=2±sqrt(5).
Completing the square by factoring out a negative one
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