Question

Quala a equação do 2 grau×2-×-20=0

Answer 1

Bom dia!

x²-x -20 = 0

a = 1

b= 1

c = -20

∆ = b² -4.a.c

∆ = 1²-4.1.(-20)

∆ = 1 +80

∆ = 81

x= -b ± √∆/ 2.a

x= -1 ±√81/2

x= -1+9 /2

x= 8/2

x=4

x" = -1-9/2

x" = -5

S = {-5,4}

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