Final answer:
To solve the quadratic equation x²+18x+66=0 by completing the square, reorder the equation, complete the square, factor the perfect square, take the square root, and write the solutions.
Step-by-step explanation:
To solve the quadratic equation x²+18x+66=0 by completing the square:
- Reorder the equation so that the constant term (66) is on one side and the variable terms (x² and 18x) are on the other side.
- Complete the square by adding the square of half the coefficient of x to both sides of the equation.
- Factor the perfect square on the left side of the equation and simplify.
- Take the square root of both sides to solve for x.
- Finally, write the two solutions for x.
Therefore, the solutions for the quadratic equation x²+18x+66=0 are x=-3 and x=-11.