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

Answer:

51 or 53

Step-by-step explanation:

135=176-.8(52)

Answer 2

Answer: 51 years

Step-by-step 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

$A=\dfrac{176-M}{0.8}=220-1.25M$

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.