Question

Y is inversely proportional to x.

Answer 1

Answer:

see explanation

Step-by-step explanation:

Given that y is inversely proportional to x then the equation relating them is

y = $\frac{k}{x}$ ← k is the constant of proportionality

To find k use the condition that y = 7, x = 9

k = yx = 7 × 9 = 63, thus

y = $\frac{63}{x}$ ← equation of proportion

When x = 21, then

y = $\frac{63}{21}$ = 3