Question 982840
Better understanding is  PER STUDENT.
Privately,  25 dollars PER STUDENT;
Group, 18 dollars PER STUDENT.


p, private students
g, grouped students
-
{{{system(p+g=12,25p+18g=265)}}}


Try elimination method to start.  Student count equation done as  {{{18p+18g=12*18}}}
{{{18p+18g=216}}}


Equivalent System
{{{system(18p+18g=216,25p+18g=265)}}}


{{{(25p+18g)-(18p+18g)=265-216}}}
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