Question

Решите уравнения а)x во 2 степени=0,49 б)x во 2 степени = 10

Answer 1

$1)\; \; x^2=0,49\\\\\sqrt{x^2}=\sqrt{0,49}\qquad (\; \sqrt{x^2}=|x|\; ) \\\\|x|=0,7\\\\x=\pm 0,7\\\\2)\; \; x^2=10\\\\x^2-10=0\\\\(x-\sqrt{10})(x+\sqrt{10}))=0\\\\x-\sqrt{10}=0\; \; \; ili\; \; \; \; x+\sqrt{10}=0\\\\x=\sqrt{10}\; \; \; ili\; \; \; x=-\sqrt{10}$