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35 votes
Solve by factoring x^2 + 6x = -9 Hint: this is a double root

the answer isn't +/-15

User Nibir
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1 Answer

20 votes
20 votes

Answer:

x = -3, -3

Explanation:


{x}^(2) + 6x = - 9 \\ \\ \implies \: {x}^(2) + 6x + 9 = 0 \\ \\ \implies \: {x}^(2) + 3x + 3x+ 9 = 0 \\ \\ \implies \: x(x + 3) + 3(x + 3) = 0 \\ \\ \implies \: (x + 3)(x + 3) = 0\\ \\ \implies \: x + 3 = 0 \: \: or \: \: x + 3 = 0 \\ \\ \implies \: x = - 3 \: \: or \: \: x = - 3 \\ \\ \implies \: x = - 3, \: \: - 3

User Borophyll
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