- #1

xtrubambinoxpr

- 87

- 0

## Homework Statement

See attached image

## Homework Equations

they are provided in the image. I see the domain is used

## The Attempt at a Solution

I can't figure out how they went from step one to step 2. where does the -81 come from and the 9 multiplied to the function in the middle. I tried to figure it out and all i got was divide everything by 9 then multiplying by 18 across to get 9 in the middle but that won't get me 81 on the eft hand side.

Thank you in advance!