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What are the possible values of x in 8x2 + 4x = -1?

User Makhiel
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1 Answer

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Answer: x only can have complex values, not real values.


x = -1/4 - 1/4i and x = -1/4 + 1/4 i


Step-by-step explanation:


Finding the possible values of x in the expression given is solving the quadratic equation.


8x² + 4x = - 1

Rearrange the terms:


8 (x² + x/2) = - 1 ← common factor 8 in the left side


x² + x/2 = - 1/8 ← division property

x² + x/2 + 1/16 = - 1/8 + 1/16 ← addition property

(x + 1/4)² = -1/8 + 1/16 ← -factor the perfect square trinomial in the left side


(x + 1/4)² = - 1/16 ← add the fractions in the right side


x + 1/4 = (+/-) √ (-1/16) ← square roots on both sides


x + 1/4 = (+/-) (1/4)i ← complex solution


x = - 1/4 +/- 1/4i


x = - 1/4 - 1/4i and x = - 1/4 + 1/4 i ← answer
User Stu Cox
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