Question 1174771
x = # of $10 tickets 
y = # of $20 tickets
<pr>
x + y = 8800
10x + 20y = 137000
<pr>
Multiply first equation by -20:
<pr>
-20(x + y) = -20(8800)
<pr>
-20x - 20y = -176000
<pr>
Here are your two equations:
<pr>
-20x - 20y = -176000
10x + 20y = 137000
<pr>
Add the two equations together:
<pr>
-10x = -39000
<pr>
Solve for x:
<pr>
x = 3900
<pr>
Plug in x = 3900 into the original first equation:
<pr>
x + y = 8800
<pr>
3900 + y = 8800
<pr>
Solve for y:
<pr>
y = 4900
<pr>
x = # of $10 tickets = <b>3900</b>
y = # of $20 tickets = <b>4900</b>