Question

решите уравнение : x в 4степени=80

Answer 1

$x^4=80\\x^4-80=0\\(x^2-sqrt{80})(x^2+sqrt{80})=0,\\sqrt{80}=sqrt{16cdot 5}=4sqrt5\\(x-sqrt{4sqrt{5}})(x+sqrt{4sqrt{5}})(x^2+4sqrt5)=0\\(x-2sqrt[4]5)(x+2sqrt[4]{5})(x^2+4sqrt5)=0\\x_1=2sqrt[4]{5},; x_2=-2sqrt[4]{5}$