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4x2 + 4x + 10 = 0
Solve by quadratic formula

1 Answer

3 votes

Answer:

x = -1/2 + (3 i)/2 or x = -1/2 - (3 i)/2

Explanation:

Solve for x:

4 x^2 + 4 x + 10 = 0

Divide both sides by 4:

x^2 + x + 5/2 = 0

Subtract 5/2 from both sides:

x^2 + x = -5/2

Add 1/4 to both sides:

x^2 + x + 1/4 = -9/4

Write the left hand side as a square:

(x + 1/2)^2 = -9/4

Take the square root of both sides:

x + 1/2 = (3 i)/2 or x + 1/2 = -(3 i)/2

Subtract 1/2 from both sides:

x = -1/2 + (3 i)/2 or x + 1/2 = -(3 i)/2

Subtract 1/2 from both sides:

Answer: x = -1/2 + (3 i)/2 or x = -1/2 - (3 i)/2

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