Need help with Algebra word problem

Question

Karly's dog weighs 60 pounds. The veterinarian told her that a healthy weight for her dog would be less than 45 pounds. If Karly's dog can lose an average of 0.8 per week on a certain diet, how lon will it take the dog to reach a healthy weight?

Answer 1

60 - .8w = 45 (60 lbs and losing .8 lbs a week for a number of weeks until we hit 45)

subtract 60:

-.8w = -15

divide by -.8

w = 18.75

 

18.75 weeks