# Can every quadratic be solved by using the completing the square method?

##### 1 Answer

Can every quadratic be solved by using the completing the square method? Yes, it sure seems so.....but, I wouldn't want to do it that way every time!!

Certainly, every quadratic can be solved by the quadratic formula, but I also wouldn't want to use it every time either.

I think you should develop some strategies for which method is best in which circumstances. Purple Math link

There are even websites that will solve the problems for you: Solver

For completing the square, I look for two things: "1" as the lead coefficient (on the

Example: Solve

Step 1:

Step 2: take half of the "4", and square that number.

Step 3: Add that number to both sides

Step 4: Factor the trinomial:

Step 5: Take the square root of both sides:

Step 6:

Step 7:

Phew, that's a lot of steps! And it definitely takes practice. One more example:

Solve

so, x = 9 or -1. Wow!

Of course, those nice, rational answers tell me that the original problem could have been solved by factoring: (x-9)(x+1)=0

Use the zero product property to solve x = 9 or x = -1.