The values of [tex]x[/tex] are required.
The values are [tex]x=-2+\sqrt{5},-2-\sqrt{5}[/tex]
Quadratic equations
The given equation is
[tex]x^2+4x-1=0[/tex]
The required formula to solve the equation [tex]ax^2+bx+c=0[/tex] is
[tex]x=\dfrac{-b\pm\sqrt{b^2-4ac}}{2a}[/tex]
Here,
[tex]a=1[/tex]
[tex]b=4[/tex]
[tex]c=-1[/tex]
Substituting the values
[tex]x=\dfrac{-4\pm \sqrt{4^2-4\times1\times\left(-1\right)}}{2\times 1}\\\Rightarrow x=-2+\sqrt{5},-2-\sqrt{5}[/tex]
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