Question

How do you solve `7r \div 7= 21\div 7`?

Answer 1

`r=3`

Explanation:

First multiply both sides by `7` and cancel
`7rcolor(red)cancel(color(black)(-:7))color(red)cancel(color(black)(xx7))=21color(red)cancel(color(black)(-:7))color(red)cancel(color(black)(xx7))`
`7r=21`

Next divide both sides by `7` and cancel

`(color(red)cancel(color(black)(7))r)/color(red)cancel(color(black)(7))=21/7`
`r=21/7`

Simplify
`r=(3*color(red)cancel(color(black)(7)))/color(red)cancel(color(black)(7))`
`r=3`

Answer 2

`r=3`

Explanation:

The divisions can be written in fraction form:

`(7r)/7 = 21/7" "larr`simplify each side.

`(cancel7r)/cancel7 = 21/7`

`r = 3`

Answer 3

`(7r)/7=21/7`
`r=3`
Verification:
`{7(3)}/7=21/7`
`21/7=21/7`
`3=3`