Question 1063449
advanced: x
at door: y
---------
x+y = 2,825 
thus
y = 2,825-x
:
8x+10y = 25,898 substitute for y
8x+10(2,825-x) = 25,898
8x+28,250-10x = 25,898
-2x = -2352 divide both sides by -2 and remember -/- = 
x = 1,176 This is how many advanced tickets were sold. And:
2,825-1,176 = 1,649 tickets were sold at the door