Question

x2-8×+9=0 me ajudem?

Answer 1

${x}^{2} - 8x + 9 = 0 \\ \\ delta = 64 - 36 = 28 \\ \\ x = \frac{8 + \sqrt{28} }{2} = \frac{8 + 2 \sqrt{7} }{2} = 4 + \sqrt{7} \\ \\ x = \frac{8 - \sqrt{28} }{2} = \frac{8 - 2 \sqrt{7} }{2} = 4 - \sqrt{7}$