Question

Quais as raízes dessa equação x2-13x+42=0

Answer 1

x² - 13x + 42 = 0

Δ = b² - 4.a.c  <- formula 
Δ = 13² - 4.1.42
Δ = 169 - 168
Δ = 1 

$\frac{-b + - \sqrt{delta} }{2.a}$  <-- formula.
$\frac{-13 + - \sqrt{1} }{2.1}$

x' = $\frac{-13 + 1 }{2} = -12$
x'' = $\frac{-13 - 1 }{2} = -14$