Respostas
a)
Δ = b² - 4.a.c
Δ = (-3)² - 4 . 2 . (-5 )
Δ = 9 - 4. 2 . -5
Δ = 49
x = (-b +- √Δ)/2a
x' = -(- 3 + √49)/2.2 x'' = -(- 3 - √49)/2.2
x' = 10 / 4 x'' = - 4 / 4
x' = 5 / 2 x'' = - 1
b)
Δ = b² - 4.a.c
Δ = (-6)² - 4 . 1 . 9
Δ = 36 - 4. 1 . 9
Δ = 0
x = (-b +- √Δ)/2a
x' = -(-6 + √0)/2.1
x' = 6 / 2
x' = 3 x'' = 3
c) x² - 3x + 0 = 0
Δ = b² - 4.a.c
Δ = (-3)² - 4 . 1 . 0
Δ = 9 - 4. 1 . 0
Δ = 9
x = (-b +- √Δ)/2a
x' = -(-3 + √9)/2.1 x'' = -(-3 - √9)/2.1
x' = 6 / 2 x'' = 0 / 2
x' = 3 x'' = 0
d)
4x² = 4
x² = 4 / 4
x² = 1
x = ±√1
x' = 1 e x'' = - 1
e)
Δ = b² - 4.a.c
Δ = (-7)² - 4 . 1 . 10
Δ = 49 - 4. 1 . 10
Δ = 9
x = (-b +- √Δ)/2a
x' = -(-7 + √9)/2.1 x'' = -(-7 - √9)/2.1
x' = 10 / 2 x'' = 4 / 2
x' = 5 x'' = 2
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