Question

como resolver x² - 4x + 5 = 0?

Answer 1

a=1 b=-4 c=-5
Δ=b²-4ac
Δ=(-4)²-4.1.(-5)
Δ=16+20
Δ=36

x=-b±√Δ/2.a
x=-(-4)±√36/2.1
x= 4±6/2

x'= 4+6/2=10/2=5
x''= 4-6/2=-2/2=-1

S(5,-1)

Bons estudos!