Question

x² - 2x - 5 =0 quanto é?

Answer 1

X² - 2x - 5 =0
Δ=b²-4.a.c
Δ=(-2)²-4.1.(-5)
Δ=4+20
Δ=25

X=-b+-√Δ/2.a
X=-(-2)+-√25/2.1
X=+2+-5/2
X,=+2+5/2=7/2
X,,=+2-5/2=-3/2