Answer:
1. [tex]x = \pm 5[/tex]
2. [tex]x = \pm i[/tex]
3. [tex]x = 5, -4[/tex]
Step-by-step explanation:
1.
[tex]x^2-25=0[/tex]
[tex]x^2 = 25[/tex]
[tex]x = \pm \sqrt{25}[/tex]
[tex]x = \pm 5[/tex]
2.
[tex]x^2 + 1 = 0[/tex]
[tex]x^2 = -1[/tex]
[tex]x = \pm \sqrt{x-1}[/tex]
[tex]x = \pm i[/tex]
3.
[tex]x^2=x+20[/tex]
[tex]x^2 - x - 20 = 0[/tex]
[tex](x-5)(x+4)=0[/tex]
[tex]x = 5, -4[/tex]
