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25 votes
25 votes
Please give a step-by-step solution of 2x^2 +12x = 6 (by completing the square)

User Princepangaea
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1 Answer

25 votes
25 votes

Answer:

x = - 3 ± 2
√(3)

Explanation:

Given

2x² + 12x = 6 ( divide through by 2 )

x² + 6x = 3

To complete the square

add ( half the coefficient of the x- term )² to both sides

x² + 2(3)x + 9 = 3 + 9

(x + 3)² = 12 ( take the square root of both sides )

x + 3 = ±
√(12) = ± 2
√(3) ( subtract 3 from both sides )

x = - 3 ± 2
√(3) ← exact solutions

User SHODAN
by
3.1k points