Question

X2-4×=5
(×-4)+15-×=27
X+1).(x-2)=-7×-10
Equaçao do 2 grau

Answer 1

Olá Vitoria 

x² - 4x = 5

x² - 4x - 5 = 0

delta
d² = 16 + 20 = 36
d = 6

x1 = (4 + 6)/2 = 10/2 = 5
x2 = (4 - 6)/2 = -2/2 = -1

(x - 4)*(15 - x) = 27

-x² + 19x - 60 = 27

x² - 19x + 87 = 0

delta
d² = 19² - 4*87 = 361 - 348 = 13
d = √13

x1 = (19 + √13)/2
x2 = (19 - √13)/2

(x + 1)*(x - 2) = -7x - 10

x² - x - 2 = -7x - 10

x² + 6x + 8 = 0

delta
d² = 36 - 32 = 4
d = 2

x1 = (-6 + 2)/2 = -4/2 = -2
x2 = (-6 - 2)/2 = -8/2 = -4 

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