X2+2x+8=0 solve by completing the square

x = i sqrt(7) - 1 or x = -i sqrt(7) - 1

Step-by-step explanation:

Solve for x:

x^2 + 2 x + 8 = 0

Subtract 8 from both sides:

x^2 + 2 x = -8

Add 1 to both sides:

x^2 + 2 x + 1 = -7

Write the left hand side as a square:

(x + 1)^2 = -7

Take the square root of both sides:

x + 1 = i sqrt(7) or x + 1 = -i sqrt(7)

Subtract 1 from both sides:

x = i sqrt(7) - 1 or x + 1 = -i sqrt(7)

Subtract 1 from both sides:

 x = i sqrt(7) - 1 or x = -i sqrt(7) - 1

So basically all you need to do is divide 108 dollars by 12 movie tickets (108/12) which gives you the answer 9.

So $9 per ticket