1. The problem states that Meredith's cellular cost varies directly with the number of weeks she uses her phone. This means the relationship can be written as $$y = kx$$ where $$y$$ is the cost, $$x$$ is the number of weeks, and $$k$$ is the constant of proportionality. 2. To find $$k$$, use one pair of values from the table. For example, when $$x = 3$$ weeks, $$y = 21$$. 3. Substitute these values into the equation: $$21 = k \times 3$$ 4. Solve for $$k$$: $$k = \frac{21}{3} = 7$$ 5. Therefore, the equation representing the relationship is: $$y = 7x$$ 6. Comparing this with the options, the correct answer is A. $$y = 7x$$.