Question

Alguem pode me ajudar a resolver essas tres equaçoes ?? Porfavor !!


1. 4z² + 7z = 0 

2. b² + 7 = 0 

3. k² - k + 8 = 0 

Answer 1

$4z^2+7z=0\\z(4z+7=0)\\z=\frac{-7}{4}\\\\b^2+7=0\\b^2=-7\\b'= \sqrt{7} \\b''= -\sqrt{7} \\\\k^2-k+8=0\\\Delta=1-4.8=31\\x'=\frac{1+ \sqrt{31} }{2}\\x''=\frac{1- \sqrt{31} }{2}$