Use the quadratic formula to solve x2 + 8x = –2.

Question

anonymous · Answer

Solve for x over the real numbers:
$$x^2+8 x = -2$$
Take one half of the coefficient of x and square it, then add it to both sides.
Add 16 to both sides:
$$x^2+8 x+16 = 14$$
Factor the left hand side.
Write the left hand side as a square:
$$(x+4)^2 = 14$$
Eliminate the exponent on the left hand side.
Take the square root of both sides:
$$x+4 = sqrt(14) $$
Look at the first equation:  Solve for x.

espex · Answer

@fernmndez that is completing the square, the instructions state to use the quadratic formula. $$\frac{-b\pm\sqrt{b^2-4ac}}{2a}$$

anonymous · Answer

@eSpeX  :( Sorry. I might've had a minor stroke. Not sure how I missed that..

goformit100 · Answer

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