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Solve by completing the square x^2+6x+13=0

User Stukelly
by
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1 Answer

4 votes

Answer:

x = -3 + 2 i or x = -3 - 2 i

Explanation:

Solve for x:

x^2 + 6 x + 13 = 0

Hint: | Solve the quadratic equation by completing the square.

Subtract 13 from both sides:

x^2 + 6 x = -13

Hint: | Take one half of the coefficient of x and square it, then add it to both sides.

Add 9 to both sides:

x^2 + 6 x + 9 = -4

Hint: | Factor the left hand side.

Write the left hand side as a square:

(x + 3)^2 = -4

Hint: | Eliminate the exponent on the left hand side.

Take the square root of both sides:

x + 3 = 2 i or x + 3 = -2 i

Hint: | Look at the first equation: Solve for x.

Subtract 3 from both sides:

x = -3 + 2 i or x + 3 = -2 i

Hint: | Look at the second equation: Solve for x.

Subtract 3 from both sides:

Answer: x = -3 + 2 i or x = -3 - 2 i

User Serkan Durusoy
by
4.7k points