Question

х2-2|х|-8=0 помогите пожалуйста срочно!! даю 40 баллов!!​

Answer 1

$\displaystyle\bf\\x^{2} -2|x|-8=0\\\\x^{2} =|x|^{2} \\\\|x|^{2} -2|x|-8=0\\\\|x|=m \ \ ; \ \ m\geq 0\\\\m^{2} -2m-8=0\\\\D=(-2)^{2} -4\cdot(-8)=4+32=36=6^{2} \\\\\\m_{1} =\frac{2+6}{2} =4\\\\\\m_{2} =\frac{2-6}{2} =-2 < 0 \ - \ ne \ podxodit\\\\\\|x|=4\\\\x_{1} =-4 \ \ \ ; \ \ \ x_{2} =4\\\\\\Otvet \ : \ -4 \ ; \ 4$