Question

How do you solve `sqrt(x+9)=6`?

Answer 1

`x=27`

Explanation:

To 'undo' the root `color(blue)"square both sides"` of the equation.

`(sqrt(x+9))^2=6^2`

`rArrx+9=36`

subtract 9 from both sides.

`xcancel(+9)cancel(-9)=36-9`

`rArrx=27`

`color(blue)"As a check"`

Substitute this value into the left side and if equal to the right side then it is the solution.

`sqrt(27+9)=sqrt36=6=" right side"`

`rArrx=27 " is the solution"`