Question

Найдите корни квадратного трехчлена
x² - 8x + 5.

Answer 1

$x^{2} -8x+5=0\\\\D=(-8)^{2}-4*5=64-20=44=(2\sqrt{11})^{2}\\\\x_{1} =\frac{8-2\sqrt{11}}{2}=4-\sqrt{11}\\\\x_{2}=\frac{8+2\sqrt{11}}{2}=4+\sqrt{11}$