Answer:
x = 1 or x = -9
Explanation:
Solve for x over the real numbers:
x^2 + 8 x - 9 = 0
Hint: | Solve the quadratic equation by completing the square.
Add 9 to both sides:
x^2 + 8 x = 9
Hint: | 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 = 25
Hint: | Factor the left hand side.
Write the left hand side as a square:
(x + 4)^2 = 25
Hint: | Eliminate the exponent on the left hand side.
Take the square root of both sides:
x + 4 = 5 or x + 4 = -5
Hint: | Look at the first equation: Solve for x.
Subtract 4 from both sides:
x = 1 or x + 4 = -5
Hint: | Look at the second equation: Solve for x.
Subtract 4 from both sides:
Answer: x = 1 or x = -9