Question

x^2-x-90=0 resolva essa EQUAÇÃO

Answer 1

x²- x - 90 = 0

a = 1
b = -1
c = -90

Δ = b² - 4ac
Δ = 1 + 360
Δ = 361

x = (-b ± √Δ)/2a
x = (1 ± 19)/2
x' = 1 + 19/2 
x' = 10
x" = 1 - 19 / 2
x" = -18/2
x" = -9