Question

(x-5) ao quadrado menos 10x

Answer 1

(5 - x)² - 10x
(5 - x) . (5 - x) - 10x
25 - 5x - 5x + x² - 10x = 0
x² - 20x + 25 = 0
Δ = b² - 4 . a . c
Δ = (- 20)² - 4 . 1 . 25
Δ = 400 - 100
Δ = 300

x = - b ± √Δ/2 . a
x = - (- 20) ± √300/2 . 1
x = 20 ± √2² . 3 . 5²/2
x = 20 ± 2 . 5√3/2
x = (20 ± 10√3)/2

x' = (20 + 10√3)/2
x' = [10 . (2 + √3)]/2
x' = 5 . (2 + √3)
x' = 10 + 5√3

x'' = (20 - 10√3)/2
x'' = [10 . (2 - √3)]/2
x'' = 5 . (2 - √3)
x'' = 10 - 5√3