Question

3 scale up or scale down to determine each unknown quantity. e \\(\frac{\\$40}{15 \text{ gallons}} = \frac{?}{3 \text{ gallons}}\\)

Explanation:

Step1: Let the unknown be \( x \)

We have the proportion \(\frac{40}{15}=\frac{x}{3}\)

Step2: Cross - multiply

Cross - multiplying gives us \(15x = 40\times3\)

Step3: Calculate the right - hand side

\(40\times3 = 120\), so the equation becomes \(15x=120\)

Step4: Solve for \( x \)

Divide both sides of the equation by 15: \(x=\frac{120}{15}\)

Step5: Simplify the fraction

\(\frac{120}{15}=8\)

Answer:

\( \$8 \)