Question

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. Solve the formula for A. At what age would you have a recommended maximum heart rate in beats per minute of 135?

25 Years
39 Years
51 Years
53 Years

Answer 1

51 or 53

Explanation:

135=176-.8(52)

Answer 2

Answer: 51 years

Explanation:

Given : 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.

To solve the formula for A , add 0.8A and subtract M on both sides , we get

`0.8A=176M`

Divide 0.8 on both sides , we get

`A=(176-M)/(0.8)=220-1.25M`

i.e. Formula for A :
`A=220-1.25M`

Put M= 135, we get

`A=220-1.25(135)=51.25\approx51\text{ years}`

Hence, at the age of 51 years you would have a recommended maximum heart rate in beats per minute of 135.