Question 816577
Bunch of stuff to unscramble.  Start by assigning variables.

n = how many tickets at 0.40 dollars each
m = how many tickets at 0.25 dollars each.


Immediately see, m+n=500.

Amount of money for the 40 cent tickets, 0.4*n.
Amount of money for the 25 cent tickets, 0.25*m.
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0.4n=70+0.25m.


OKay,two equations, two unknown variables; go to it!
First simplify the second, money equation:
40n=25m+70
8n=5m+14
5m-8n=14;
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The system to solve can be shown as: {{{highlight_green(5m-8n=14)}}} and {{{highlight_green(m+n=500)}}}.
NOW go to it!