<PRE><B>Question 1029592</B>
Set P = number of parent tickets
Set S = number of student tickets
P + S = 200
P*$3.00 + S*$1.00 = $450.00
3P + S = 450
Add -S to each side of the equation P + S = 200
P = 200-S
Substitute (200-S) for P in 3P + S = 450
3(200-S) + S = 450
600 -2S = 450
add -600 to each side
 -2S = -150
divide each side by 3
 S = 75
Since P = 200-S
P = 200-75 = 125
So 75 students at $1 plus 125 parents at $3 for a total of $450</PRE>