Respuesta :

bradnorris03

Answer:

r=-16

Step-by-step explanation:

21=6r+5-7r

1) Combine alike terms on the right side (6r and -7r):

21=-r+5

2) Subtract a 5 from both sides:

16=-r

3) Divide both sides by -1:

r=-16

Step-by-step explanation:

first combine like terms : 6r and -7r = -1r

21=5 -1r

cancellation cancel the same terms on both sides of the equation by inverse operations:

subtract 5 from both sides 21-5= 16 5-5=0

16=-1r

divide both ends of the equation by -1

16÷1 = 16 1÷ -1= 1

16=r