Question

Please answer and explain how to solve with quadratic formula:

What are the solutions to x^2 + 8x + 20 = 0?

Answer 1

x = -4 + 2 i or x = -4 - 2 i

Explanation:

Solve for x:

x^2 + 8 x + 20 = 0

Subtract 20 from both sides:

x^2 + 8 x = -20

Add 16 to both sides:

x^2 + 8 x + 16 = -4

Write the left hand side as a square:

(x + 4)^2 = -4

Take the square root of both sides:

x + 4 = 2 i or x + 4 = -2 i

Subtract 4 from both sides:

x = -4 + 2 i or x + 4 = -2 i

Subtract 4 from both sides:

Answer: x = -4 + 2 i or x = -4 - 2 i