Question

C-D ,sendo c=-x²+5x-1 e D= 2x²+1

Answer 1

$( - {x}^{2} + 5x - 1) - (2 {x}^{2} + 1) = - {x}^{2} + 5x - 1 - 2 {x}^{2} - 1 = - 3 {x}^{2} + 5x - 2 \\ delta = {5}^{2} - 4.( - 3).( - 2) \\ delta =25 - 24 \\ delta = 1 \\ x = \frac{ - 5 + 1}{ - 6} = \frac{ - 4}{ - 6} = \frac{4}{6} = 0.67 \\ x = \frac{ - 5 - 1}{ - 6} = \frac{ - 6}{ - 6} = 1$