Question

sendo x' e x'' as raizes da equação 2x² - 8x + 5 = 0 calcule: a) x' + x''...

Answer 1

2x² - 8x + 5 = 0 

Δ = b²-4ac
Δ = (-8)²-4(2)(5)
Δ = 64-40
Δ = 24

x' = (-b+√Δ)/2a = (8+√24)/2*2 = (8+√24)/4
x'' = (-b-√Δ)/2a = (8-√24)/2*2 = (8-√24)/4

Logo:

x'+x'' = [(8+√24)/4]+[(8-√24)/4]
x'+x'' = 4