Answer:
X=18
Y=52
Explanation:
Let X represent the first type of ticket sold at the concert
Let Y represent the second type of ticket sold at the concert-----equation 1
X + Y= 70 (Total number of tickets sold) ------equation 2
(X×10) + ( Y×12)=$804. ( Total money generated in the concert
Since,
X+Y= 70
X= 70-Y
Substitute (70-Y) for X in equation 2
(70-Y)×10 + Y×12=804
700-10Y+12Y= 804
Collect the like terms
700+2Y=804
2Y=804-700
2Y= 104
Divide both sides by the coefficient of Y which is 2
2Y/2= 104/2
Y=52
Substitute 52 for Y in equation 1
X+Y=70
X+ 52=70
collect the like terms
X= 70-52
X=18
Hence the first type of ticket sold is 18 tickets and the second type of ticket sold is 52 tickets.