During exercise, the recommended maximum heart rate in beats per minute is modeled by the formula M = 176 – 0.8A, where M is the maximum heart rate and A is the person’s age. Approximately, at what age would you have a recommended heart rate in beats per minute of 140?

1 answer

We can start by setting the formula equal to 140 and solving for A:

176 - 0.8A = 140

Subtracting 176 from both sides, we get:

-0.8A = -36

Dividing both sides by -0.8, we get:

A = 45

Therefore, at approximately 45 years of age, a person would have a recommended heart rate of 140 beats per minute during exercise.