Lie is solving the quadratic equation by completing the square.

3x2 + 18x – 8 = 0

3x2 + 18x = 8

What should Lie do next?

Write the polynomial as a binomial squared.
Factor 3 out of the variable terms.
Isolate the variable x.
Add 8 to both sides of the equation.

Question

Lie is solving the quadratic equation by completing the square.

3x2 + 18x – 8 = 0

     3x2 + 18x = 8

What should Lie do next?

Write the polynomial as a binomial squared.
Factor 3 out of the variable terms.
Isolate the variable x.
Add 8 to both sides of the equation.

mathstudent55 · Answer

When you complete the square, you must start with $x^2 + ax + b$, 
not with $ax^2 + bx + c$