Accepted Answer
x² - 25 = 0The left side is the difference of 2 squares,so we know right away, without any uncertaintyor sweat, that it can be written as (x + 5) (x - 5) ,and we know that it's equal to zero when either factor is zero.Now let's look at the choices:A. X = -1 Not a chance.B. X = -3 Also no.C. X = -5 Yes that's good; that would make the first factor zero. D. X = 5 Yes that's good too; it would make the second factor zero.E. X = 3 Not true. Don't know how they came up with it.F. X = 1 Equally not true.
Suggested Answer
[tex] x^{2} - 25 = 0 \\ x^{2} = 0 + 25 \\ x^{2} = 25 \\ x = \pm \sqrt{25} \\ \boxed{x = \pm 5}[/tex]correct alternatives : C , D