Question

$- {x}^{2} - x + 20 = 0$

Answer 1

-x² - x + 20 = 0 *(-1)
x² + x - 20 = 0
a= 1, b= 1, c= -20

∆= 1² - 4.1.(-20)
∆= 1 + 80
∆= 81

x= -b±√∆ /2.a

x'= -1+9/2.1
x'= 8/2
x'= 4

x"= -1-9/2
x"= -10/2
x"= -5

Bons estudos! :)