How do I calculate. this. Please explain it to me. Thank u

Homework: Unit 3 HW 4.4 Linear Inequalities in Two Variables Score: 0 of 1 pt 11 of 11 (10 complete) 4.4.59 The graph on the right shows the solution set of the given system of inequalities, where H is the heart rate and a is Target Heart Rate for Weight Loss the age, for the target heart rate of a particular exercise goal as a function of the age of the person exercising Answer parts a and b. HA 10 sas 70 Range of ages H20.6(220 - a) Minimum target rate Heart Rate (beats per minute 160- 140- H= 0.7(220 -a) a- 10 A HS0.7(220 - a) Maximum target rate 120- 100- H= 0.6(220 - a) .B a = 70 80- a 0 10 20 30 40 50 60 70 80 90 Age a. What are the coordinates of point B and what does this mean in terms of age and heart rate? The coordinates of point B are . (Typis an ordered pair.) More Enter your answer in the answer box and then click Check Answer. 2 parts remaining Clear All Type here to search O e a 9