Two quantities, x and y, are in direct variation when the ratio of the two quantities is constant. In a situation of direct variance, the constant is the "constant of proportionality
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a is directly proportinal or inversely proportional to b.
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( də′rekt ′ver·ē′ā·shən ) (mathematics) A relationship between two variables wherein their ratio remains constant. An equation
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Equation: y = 4x Variable y is directly proportional to x. Doubling x
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