We are given with a quadratic equation and have to find its solution(s) :
[tex]{:\implies \quad \sf 40-x^{2}=0}[/tex]
Transpose x² to RHS ;
[tex]{:\implies \quad \sf x^{2}=40}[/tex]
[tex]{:\implies \quad \sf x=\pm \: \sqrt{40}}[/tex]
[tex]{:\implies \quad \sf x=\pm \: \sqrt{2\times 2\times 2\times 5}}[/tex]
[tex]{:\implies \quad \sf x=\pm \sqrt{\underline{\underline{2\times 2}}\times 2\times 5}}[/tex]
[tex]{:\implies \quad \bf \therefore \quad \underline{\underline{x=\pm 2\sqrt{10}}}}[/tex]
