Answer:
Root Pressure is the answer
let
x--------> the monthly fee
y--------> the administration fee
we know that
--------> equation 
--------> equation 
Multiply by
equation 
------> equation 
Adds equation
and equation 

Find the value of y

therefore
the answer is
the administration fee is equal to 
Lucas equation for his location is x(t) = 13t.
Alfonso's equation is x(t) = 238 - 21t
If you equate these, you get:
13t = 238 - 21t =>
34t = 238
t = 7
So after seven hours they meet.
They both have 4 congruent sides and angles.