Question 913190
<a href="http://www.algebra.com/my/mixture-price-two-part-both-parts-unknown.lesson?content_action=show_dev">http://www.algebra.com/my/mixture-price-two-part-both-parts-unknown.lesson?content_action=show_dev</a>


... so the hyperlink did not work.


Here is some help on the question.
L = 100 peso/kg Coffee A
H = 150 peso/kg Coffee B
T = ----------------------------
Now that I am actually analyzing the problem description, I find a major fault.
The question gives coffees of two prices, A is 100 peso/kg and B is 150 peso/kg, and the goal is to make a blend using these which will have a PRICE of 156.25 peso/kg.  This cannot occur.  The target must not be outside of the two individual priced coffees to be mixed.  THAT may well be why you had trouble with the problem, and so why you asked for help.  The problem description is WRONG.