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

3 Answers
Mar 27, 2017

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

Mar 28, 2017

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

Mar 29, 2017

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