The x-intercept of a function is when the y-value is 0.
Replace y with 0 in the equation. You get the following.
[tex]x^2-25=0[/tex]
Add both sides by 25
[tex]x^2=25[/tex]
Take the square root.
[tex]x= \pm \sqrt{25} [/tex]
[tex]= \pm 5[/tex]
This means that the x-intercepts are 5 and -5.
A is your answer.
