Question

x2-8X=X-5 como resolver essa equaçao

Answer 1

x² - 8x = x - 5

x² -9x + 5 = 0

a = 1, b= -9, c = 5

$\Delta = b^2-4.a.c\\ \Delta=(-9)^2-4.1.5\\ \Delta=81-20\\ \Delta = 61\\\\x= \dfrac{-b \pm \sqrt{ \Delta} }{2.a}\\\\\\x= \dfrac{9 \pm \sqrt{61} }{2}\\\\\\ x'= \dfrac{9 + \sqrt{61} }{2}\\\\\\\\x''= \dfrac{9 - \sqrt{61} }{2}$


Forte abraço!