How do you solve #-21r = 63#?

2 Answers
Jul 28, 2017

Divide each side of the equation by #color(red)(-21)# to solve for #r# while keeping the equation balanced:

#(-21r)/color(red)(-21) = 63/color(red)(-21)#

#(color(red)(cancel(color(black)(-21)))r)/cancel(color(red)(-21)) = -3#

#r = -3#

Jul 28, 2017

#r=-3#

Explanation:

Divide #-21# from both sides:

#cancel(-21)/cancel(-21)r=63/(-21)#

#r=-63/21#

Simplify:

#r=-3#