Question

Which of the following is a solution of x2 + 6x = −18? x = 3 − 3i x = −3 + 3i x = −6 + 3i x = 6 − 3i

Answer 1

Step 1 ) Move all terms right side of the equation.

$\displaystyle\ x^{2} + 6x = -18$

$\displaystyle\ x^{2} + 6x + 18 = -18 + 18$

$\displaystyle\ x^{2} +6x + 18 = 0$

Step 2 ) Apply quadratic formula. (Note: There are 2 solutions)

$\displaystyle\ x^{2} +6x + 18 = 0$

$\displaystyle\ x = \frac{-b\sqrt{b^{2}-4ac}}{2a}, \displaystyle\ x = \frac{-b-\sqrt{b^{2}-4ac}}{2a}$

$\displaystyle\ x = \frac{-6+\sqrt{6^{2}-4 * 18}}{2} , \displaystyle\ x = \frac{-6-\sqrt{6^{2}-4*18}}{2}$

$\displaystyle\ x = \frac{-6+6i}{2}$ ,

$\displaystyle\ x = \frac{-6-6i}{2}$

Step 3 ) Simplify.

$\displaystyle\ x = \frac{-6+6i}{2}$ ,

$\displaystyle\ x = \frac{-6-6i}{2}$

$\displaystyle\ x = -3+ 3i$,

$\displaystyle\ x = -3 - 3i$

Since the options only provide one of the answer we found, the answer is...

$\displaystyle\ x = -3 - 3i$

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- Marlon Nunez

Answer 2

Answer:

x=-3+3i

Step-by-step explanation:

since it could either be x=-3+3i or x=-3-3i. the answer only allows for x=-3+3i then that is your answer.