Question

How do you solve `(2r-5)^2=81`?

Answer 1

`r=7`
`r=-2`

Explanation:

`(2r-5)^2=81`
or
`2r-5=+-sqrt81`
or
`2r-5=+-9`
or
`2r=5+-9`
or
`r=(5+-9)/2`
or
`r=(5+9)/2`
or
`r=14/2`
or
`r=7`-------------Ans `1`
or
`r=(5-9)/2`
or
`r=-4/2`
or
`r=-2`------------Ans `2`