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

3 Answers
Scott F.
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#

EZ as pi
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#

Atika Khan
Mar 29, 2017

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

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