Solve for x: x^2 + 4 x + 25 = 0 I ssume that's the notation. Subtract 25 from both sides: x^2 + 4 x = -25 Add 4 to both sides: x^2 + 4 x + 4 = -21 Write the left hand side as a square: (x + 2)^2 = -21 Take the square root of both sides: x + 2 = i sqrt(21) or x + 2 = -i sqrt(21) Subtract 2 from both sides: x = i sqrt(21) - 2 or x + 2 = -i sqrt(21) Subtract 2 from both sides: Answer: x = i sqrt(21) - 2 or x = -i sqrt(21) - 2