Medical researchers have determined that for exercise to be beneficial, a personâ€™s desirable heart rate, r, in beats per minute, can be approximated by the formulas r = 143 minus 0.65 a for women r = 165 minus 0.75 a for men, where a represents the personâ€™s age. if the desirable heart rate for a woman is 130 beats per minute, how old is she? a. 84 years old b. 57 years old c. 37 years old d. 20 years old

years oldwhen her heart rate is 130 beats per minute.## What are Linear Equation?

poweris 1 or maximum degree is 1. For example: x + y = 3 here the maximum degree is 1.heart rate, r = 130 beats per minute.years oldwhen her heart rate is 130 beats per minute.Linear equation” from here: https://brainly.com/question/11897796