Question

Medical researchers have determined that for exercise to be beneficial, a person’s desirable heart rate, R, in beats per minute, can be approximated by the formulas

143 - 0.65a for women
165 - 0.75a for men,

where a represents the person’s age. If the desirable heart rate for a man is 135 beats per minute, how old is he?

*question has been edited by a moderator to supply missing information*

Answer 1

Image?

Answer 2

I have edited the question to supply the missing information

Answer 3

Setup an equation with the information given and the information wanted, make them equal each other.

Your equation should look like this: 165-0.75(a) = 135
From there, solve for a to find the solution. (age)