Hope this helps you and good-luck
125 > 50 + 4.25*p
subtract 50 from each side
75 =>4.25p
divide by 4.25
p>17.64
He may invite up to 17 people ( if he doesn't have to pay for himself)
He may invite 16 if he has to pay for himself
(x-3)(x+4). -3,4 multiply to -12, and add to get 1
Let
x--------> the number of sessions
y-------> the total payment
we know that
without membership:
--------> equation 
with membership:
--------> equation 
using a graph tool------> resolve the system of equations
see the attached figure
the solution is the point 
that means
For 
the cost is
in both forms
so
to justify buying the membership

therefore
<u>the answer is</u>
