Answer:
[tex]\mathrm{Decimal}:\quad x=-6.58578\ ,\:x=-9.41421[/tex]
Step-by-step explanation:
[tex]\left(x+8\right)^2-2=0\\\mathrm{Add\:}2\mathrm{\:to\:both\:sides}\\\left(x+8\right)^2-2+2=0+2\\Simplify\\\left(x+8\right)^2=2\\\mathrm{For\:}\left(g\left(x\right)\right)^2=f\left(a\right)\mathrm{\:the\:solutions\:are\:}g\left(x\right)=\sqrt{f\left(a\right)},\:\:-\sqrt{f\left(a\right)}\\\mathrm{Solve\:}\:x+8=\sqrt{2}:\quad x=\sqrt{2}-8\\x+8=\sqrt{2}\\\mathrm{Subtract\:}8\mathrm{\:from\:both\:sides}\\x+8-8=\sqrt{2}-8\\\mathrm{Simplify}\\x=\sqrt{2}-8[/tex]
[tex]\mathrm{Solve\:}\:x+8=-\sqrt{2}:\quad x=-\sqrt{2}-8\\x+8=-\sqrt{2}\\\mathrm{Subtract\:}8\mathrm{\:from\:both\:sides}\\x+8-8=-\sqrt{2}-8\\\mathrm{Simplify}\\x=-\sqrt{2}-8\\\mathrm{The\:solutions\:to\:the\:quadratic\:equation\:are:}\\x=\sqrt{2}-8,\:x=-\sqrt{2}-8\\\mathrm{Decimal}:\quad x=-6.58578 ,\:x=-9.41421[/tex]
