Answer:
x = -2 + i or x = -2 - i
Step-by-step explanation:
Solve for x:
3 x^2 = -12 x - 15
Add 12 x + 15 to both sides:
3 x^2 + 12 x + 15 = 0
Divide both sides by 3:
x^2 + 4 x + 5 = 0
Subtract 5 from both sides:
x^2 + 4 x = -5
Add 4 to both sides:
x^2 + 4 x + 4 = -1
Write the left hand side as a square:
(x + 2)^2 = -1
Take the square root of both sides:
x + 2 = i or x + 2 = -i
Subtract 2 from both sides:
x = -2 + i or x + 2 = -i
Subtract 2 from both sides:
Answer: x = -2 + i or x = -2 - i
