Answer
Yes. The result both gives -1.
Step-by-step explanation:
The expressions are [tex]g^2-2gh-h^2[/tex] and [tex]-g(g+2h-1) -h^2[/tex]
If he substituted g=0 and h=1
[tex]g^2-2gh-h^2=0^2-(2X0X1)-1^2=0-0-1=-1[/tex]
[tex]-g(g+2h-1) -h^2=-0(0+(2X1)-1)-1^2=0-1=-1[/tex]
[tex]-1^2=-1 and 0X a=0[/tex]
The result both gives -1.