She bought 54 child tickets and 19 adult tickets.
Step-by-step explanation:
No. of tickets purchased = 73
Cost of tickets = $771
Cost of one child ticket = $9
Cost of one adult ticket = $15
Let,
Child ticket = x
Adult ticket = y
According to given statement;
x+y=73 Eqn 1
9x+15y=771 Eqn 2
Multiplying Eqn 1 by 9;
Subtracting Eqn 3 from Eqn 2;
Dividing both sides by 6;
Putting y=19 in Eqn 1
She bought 54 child tickets and 19 adult tickets.
Keywords: linear equations, subtraction
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