Answer:
D
Step-by-step explanation:
Start by subtracting 64 from both sides:
[tex]25x^2=225[/tex]
Factor this by taking roots. Divide both sides by 25 first:
[tex]x^2=9[/tex]
We "undo" a square by taking the square roots of both sides. Taking the square root leaves the possibilities of both the positive and negative roots of 9. Therefore, the solutions to this are
[tex]x=\sqrt{3},-\sqrt{3}[/tex]
