Respuesta :
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