Question

Encontre as raizes das equações x2-8x+7=0

Answer 1

$x {}^{2} - 8x + 7 = 0 \\ x = \frac{ - b + - \sqrt{ b {}^{2} - 4 \times a \times c } }{2 \times a} \\ x = \frac{ - ( - 8) + - \sqrt{ -( - 8) {}^{2} - 4 \times 1 \times 7 } }{2 \times 1} \\ x = \frac{8 + - \sqrt{64 - 28} }{2} \\ x = \frac{8 + - \sqrt{36} }{2} \\ x = \frac{8 + - 6}{2} \\ x 1 = \frac{8 + 6}{2} = \frac{14}{2} = 7 \\ x2 = \frac{8 - 6}{2} = \frac{2}{2} =1 \\ \\ as \: raizes \: sao \: 7 \: e \: 1$