7x²-2=0
add 2 to both sides
7x²=2
divide by 7 both sides
[tex]x^2=\frac{2}{7}[/tex]
sqrt both sides
[tex]x=+/-\frac{\sqrt{2}}{\sqrt{7}}[/tex]
[tex]x=+/-\frac{\sqrt{14}}{7}[/tex]
so the possible values of x are
[tex]x=\frac{5}{2},\frac{-\sqrt{14}}{7},\frac{\sqrt{14}}{7}[/tex]
