Question

Como determinar a raiz x2-4x+4=9

Answer 1

Ola Cicu

x² - 4x + 4 = 9

x² - 4x - 5 = 0

delta
d² = 16 + 20 = 36
d = 6

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

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se √(x² - 4x + 4) = 9

x² - 4x + 4 = 81

x² - 4x - 77 = 0

delta
d² = 16 + 308 = 324
d = 18

x1 = (4 + 18)/2 = 22/2 = 11
x2 = (4 - 18)/2 = -14/2 = -7 

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Answer 2

√x² + 4x + 4 = 9
x + 4x + 4 - 9 = 0
5x - 5 = 0
5x = 5
x = 5/5
x = 1