Question

equação 2 grau : x2 + 9x + 8 = 0

Answer 1

x²+9x+8=0
$\frac{-9+- \sqrt{9^2-4*1*8} }{2*1} = \frac{-9+- \sqrt{49} }{2}= \frac{-9+-7}{2}$
x1= (-9+7)/2= -2/2= -1
x2= -16/2= -8

Answer 2

x² + 9x + 8 = 0

A= 1

B= 9

C= 8

∆= b² - 4ac

∆= 9² - 4 • 1 • 8

∆= 81 - 32

∆= 49

x= - b ± √ ∆ /2a

x= - 9 ±√49 / 2 • 1

x'= - 9 + 7/2 = - 2/2 = - 1

x''= - 9 - 7/2 = - 16/2 = - 8

S= ( - 8 , - 1)