Question

ordered pair that satisfy (28,21)

Answer 1

$$\bf \text{(28, 21)} = (x, y)\\
\text{using direct variation}\\
y = (n)x \\
\text{when x= 28, y =21}\\
21 = 28n \implies n = \cfrac{21}{28} \implies \cfrac{3}{4}\\
\text{thus}\\
y = \cfrac{3}{4}x
$$

Answer 2

so if you want another ordered pair with that direct variation, just plug a value for "x" and get "y"

say if x =4, what's "y"?