Answer:
- 12x +15y = 4140; x + y = 300
- x = 120; y = 180
Step-by-step explanation:
The first equation is for receipts. Each x ticket generated $12 in receipts, so the first term needs to be 12x. Each y ticket generated $15 in receipts, so the second term needs to be 15y. U in this set of equations is the total number of tickets, said to be 300.
The equations are ...
12x +15y = 4140; x +y = 300
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Using the second equation to write an expression for x, we have ...
x = 300 -y
Substituting this into the first equation gives ...
12(300 -y) +15y = 4140
3600 +3y = 4140
y = (4140 -3600)/3 = 180
x = 300 -180 = 120
The number of tickets sold is ...
$12 tickets -- 120
$15 tickets -- 180
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You might want to notice that the equation we ended up with:
4140 -12(300) = 3y
is equivalent to this "word solution." This can be done in your head; no equations required.
If all the tickets sold were $12 tickets, the revenue would be $3600. The revenue is $540 more than that. Each $15 ticket generates $3 more revenue than a $12 ticket, so to have $540 more revenue, we must have 540/3 = 180 $15 tickets.
