How can I solve for z? 3+sqrt(z-6)=sqrt(z+9)

Printable View

- Jan 8th 2013, 06:09 PMEspionageBasic Square Root Help
How can I solve for z? 3+sqrt(z-6)=sqrt(z+9)

- Jan 8th 2013, 06:31 PMtopsquarkRe: Basic Square Root Help
This is going to be a problem in two steps. The base example here is how to solve the following for z:

The general rule is to isolate the square root, then square both sides. In your problem we need to do this*twice*.

So

One square root is already isolated, so square both sides:

Now isolate the square root:

And square both sides.

Always always always when you get a final answer for z make sure it is a solution to the original equation. Extra solutions tend to come out that don't satisfy the original equation.

-Dan - Jan 8th 2013, 06:41 PMEspionageRe: Basic Square Root Help
Where does the 6 come from when you square both sides the first time?

- Jan 8th 2013, 07:54 PMDevenoRe: Basic Square Root Help

because: