Answer:
[tex]x=\pm\sqrt{y+64}[/tex]
Step-by-step explanation:
All you need to do is isolate the x.
First, add 64 to both sides:
[tex]y=x^2-64\\x^2-64+64=y+64\\x^2=y+64[/tex]
Then, take the square root of both sides:
[tex]\sqrt{x^2}=\sqrt{y+64}\\x=\sqrt{y+64[/tex]
Actually, that is:
[tex]x=\pm\sqrt{y+64}[/tex]
Here's the reason for that. An example would be:
[tex]x^2=4[/tex]
Here, you'd take the square root of both sides to solve for x.
[tex]\sqrt{x^2}=\sqrt{4}\\x=2[/tex]
Right? But X could also be a -2, because a negative times a negative is a positive.
[tex](-2)^2=4\\-2\times-2=4\\4=4[/tex]
Therefore, [tex]x=2, -2[/tex] or [tex]x=\pm2[/tex]
[tex]x^2=2\times2=4\\x^2=-2\times-2=4[/tex]