Answer:
x = -9
x = 9
Step-by-step explanation:
[tex]x^{2} + 3 = 84[/tex]
Subtract 84 from both sides.
[tex]x^{2} + 3 - 84 = 0[/tex]
Subtract 84 from 3 to get −81.
[tex]x^{2} - 81 = 0[/tex]
Consider [tex]x^{2}[/tex] - 81. Rewrite [tex]x^{2} - 81[/tex] as [tex]x^{2} - 9^{2}[/tex]. The difference of squares can be factored in using the rule: [tex]a^{2} - b^{2} = ( a- b) ( a+ b)[/tex].
[tex](x - 9) (x + 9) = 0[/tex]
To find equation solutions, solve [tex]x - 9 = 0[/tex] and [tex]x + 9 = 0[/tex]
x = 9
x = -9
Hope it helps and have a great day! =D
~sunshine~
