Question

resolva as seguinte equação:
a) x2 - 6x + 8 + =0
b) 2x2 - 12x + 16 = 0
c) - 10x2 + 60x - 80 = 0
d) kx2 - k6x + 8k = 0

Answer 1

a)  x² - 6x + 8 + =0
Δ = b² - 4.a.c 
Δ = -6² - 4 . 1 . 8 
Δ = 36 - 4. 1 . 8 
Δ = 4
x = (-b +- √Δ)/2a
x' = (--6 + √4)/2.1  
x' = 8 / 2 
x' = 4 
x'' = (--6 - √4)/2.1
x'' = 4 / 2 
x'' = 2


b) 2x² - 12x + 16 = 0
Δ = b² - 4.a.c 
Δ = -12² - 4 . 2 . 16 
Δ = 144 - 4. 2 . 16 
Δ = 16x = (-b +- √Δ)/2ax' = (--12 + √16)/2.2
x' = 16 / 4
x' = 4
x'' = (--12 - √16) /2.2 
x'' = 8 / 4
x'' = 2

c) - 10x² + 60x - 80 = 0
Δ = b² - 4.a.c 
Δ = 60² - 4 . -10 . 80 
Δ = 3600 - 4. -10 . 80 
Δ = 6800
x = (-b +- √Δ)/2a
x' = (-60 + √6800)/2.-10
x' = -60 + √6800/ 20
x' = - 3 + √6800
x'' = (-60 - √6800)/2.-10
x'' = -60 - √6800/ 20
x'' = - 3 - √6800

d) kx² - k6x + 8k = 0 
k (x² - 6x + 8) = 0
Δ = b² - 4.a.c 
Δ = -6² - 4 . 1 . 8 
Δ = 36 - 4. 1 . 8 
Δ = 4x = (-b +- √Δ)/2ax' = (--6 + √4)/2.1x' = 8 / 2    x' = 4x'' = (--6 - √4)/2.1x'' = 4 / 2x'' = 2