SOLUTION: You burn approximately 230 calories less per hour if you ride your bike versus go on a run. Lien went on a 2-hour run plus burned an additional 150 calories in his warm up and cool

Let B is the number of calories you (actually, "average person") burn per hour riding bike (Bike; B stands for Bike), and 
let R is the number of calories you (actually, "average person") burn per hour running (Running;  R stands for Running).


Then the condition gives you these two equations


 R - B = 230,     (1)    ("You burn approximately 230 calories less per hour if you ride your bike versus go on a run. ")
2R + 150 = 4B     (2)    ("Lien and Theo burned the same amount of calories on their workouts.")



    Thus the major part of the solution is just done: the Math model is established.
    The rest is just arithmetic and techniques.
    I hope you are familiar with this technique, so I decided do not bother you with it.


Nevertheless, if the solution is still the problem to you, then let me know through the "Thank you" form,
and I will help you to complete it  (at the free of charge basis, as usual).


In this case, do not forget to refer to the ID number of this problem 1092127 in order for I could identify it.


Good luck and happy learning ! !