Solving for a Specified Variable

1.9.4 Solving for a Specified Variable

1.9.4 • Solving for a Specified Variable

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A school is holding a carnival and hopes to raise $500. Child tickets cost $3, and adult tickets cost $5. If the school sells $x$ child tickets and $y$ adult tickets, then the equation $3 x + 5 y = 500$ expresses the fact that the school raised exactly $500 from ticket sales.

Solve the equation for $x$ .

Compare your answer: $x = \frac{500 - 5 y}{3}$

Explain when it might be helpful to rewrite the equation this way.

Compare your answer: Your answer may vary, but here is a sample. Solving for $x$ helps us find out the number of child tickets to sell if we know the number of adults attending the carnival and we want to make exactly $500 from ticket sales.