Write an Equation to Describe the Variation $r$ A) $r = k a$

question 231

Multiple Choice

Write an equation to describe the variation. Use k for the constant of proportionality.
-a varies directly as $r$

• A) \(r = k a\)
• B) \(a = k r\)
• C) \(r = \frac { k } { a }\)
• D) \(a = \frac { k } { r }\)