Answer:
See explanation
Step-by-step explanation:
Let the given equation be:
[tex]5 {x}^{2} - 400 = 0[/tex]
This implies that:
[tex]5 {x}^{2} = 400[/tex]
Divide through by 5 to get;
[tex] {x}^{2} = 80[/tex]
Take square root to obtain:
[tex]x = \pm \sqrt{80} [/tex]
This implies that
[tex]x = \pm4 \sqrt{5} [/tex]
[tex]x = - 4 \sqrt{5} \: or \: x = 4 \sqrt{5} [/tex]
