<span>Let x be Joanna's heart rate immediately after running one mile.
After this heart rate x decreased by 2 over 5, Joanna's heart rate was 60 beats per minute. We can set up an equation to solve this question.
x - (2/5) x = 60
(3/5) x = 60
x = (5/3) 60
x = 300 / 3
x = 100
Joanna's heart rate immediately after running one mile was 100 beats per minute.</span>
