Answer: C) 13 gallons
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Work Shown:
(150 miles)/(6 gallons) = (325 miles)/(x gallons)
150/6 = 325/x
150*x = 6*325 .... see note below
150x = 1950
x = 1950/150 .... divide both sides by 150
x = 13 gallons is the final answer
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Note: in this step, I cross multiplied. The general template for cross multiplication is that we go from A/B = C/D to A*D = B*C. As the name implies, the "cross" refers to the "X" shape that forms when you multiply the terms.
