# How do you solve #x^2+18x=10# by completing the square?

##### 2 Answers

#### Explanation:

For completing the square, you take half the coefficient of the x value, square it, and add it. So in this case, 81 I suppose?

I apologize, I don't quite remember how to do this. However there is already a 10...

Oh! I got it!

So add 91 and then you would get:

Then you factor:

Square root:

Solve by subtracting 9:

And that should be your answer.

#### Explanation:

To complete the square a must be 1 (which it is) and:

notice we have to add c to both sides of the equation so we don't alter the value.

now factor the left side:

now we solve: