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Mathematics

2 answers:

Lesechka [4]3 years ago

8 0

Answer:

Step-by-step explanation:

x² – 8x – 9 = 0
x² – 8x = 9
x² – 8x + 16 = 9 + 16
(x – 4)² = 25
x – 4 = 25 and x – 4 = - 25 ⇒ Incorrect, should be x - 4 = 5 and x - 4 = -5
x = 29 and x = -21 ⇒ Incorrect, should be x = 9 and x = -1

earnstyle [38]3 years ago

7 0

Answer:

No, it's wrong

${x}^{2} - 8x - 9 = 0 \\ (x - 9)(x + 1) = 0 \\ x = 9 \: and \: - 1$

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