Question 875436
Normal charge, $5
Members, $4
Students, $2.5


x, y, z, for count of tickets sold as Normal, Members, Students.


{{{5x+4y+2.5z=4035}}} and {{{x+y+z=1050}}}.
The additional ticket relationship description means {{{z-x=35}}}, which is equivalent to {{{-x+0*y+z=35}}}.


You can use a matrix,
{{{(matrix(3,4,
5,4,2.5,4035,
1,1,1,1050,
-1,0,1,35))}}}


I used an online matrix calculator, http://www.math.purdue.edu/~dvb/gaussian.php ,
and found these results:
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x=225
y=565
z=260
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