How do you solve #-21 = -r -5#?

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Answer 1 · 2018-03-19T19:09:38

#r = 16#

To calculate #(r)#, we must isolate the variable onto one side:

#-21 = -(r) - 5#

Change sides

#-(r) - 5 = -21#

Add #5# to both sides

#-(r) -5 + 5 = -21 + 5#

At this point we simplify both sides:

#-(r) = -16#

And from here, we multiply both sides by #(-1)# to get our final answer in terms of positive #r#.

#r = 16#