Question

calcule as raizes da função y = -20 +9x- x²

Answer 1

delta=9²-80
delta=81-80
delta=1
$x = \frac{ - 9 + 1}{ - 2} = - \frac{ - 8}{ - 2} = \frac{8}{2} = 4$
$x = \frac{ - 9 - 1}{ - 2} = \frac{ - 10}{ - 2} = \frac{10}{2} = 5$
x=4 ou 5