Question

x²-8x +12 = 0

a)-4 e 4 c)3 e 9

b)2 e 6 d)5 e 7

Answer 1

x²-8x+12=0 

Δ=-8²-4.1.12
Δ=64-48
Δ=16

X=8+-√16/2

X'=8+4/2 = 12/2 = 6 
X''=8-4/2 = 4/2= 2 

resposta B