Question

como resolver -x²+x+2?

Answer 1

-x² + x + 2 = 0

a = -1
b = 1
c = 2

x = [- b ± √(b² - 4ac)] / 2a
x = [- 1 ± √(1² - 4 · [-1] · 2)] / 2 · (-1)
x = [- 1 ± √(1 + 8)] / -2
x = [- 1 ± √9] / -2
x = [- 1 ± 3] / -2
x' = [- 1 + 3] / -2 = 2 / -2 = -1
x'' = [- 1 - 3] / -2 = -4 / -2 = 2

S = {-1, 2}

Espero ter ajudado. Valeu!