Question

x and y vary inversely, and y = 3 when x = 6. Find y when x = 9.
A. 2
B. 4.5
C. 12
D. 18

Answer 1

"something" varies inversely to "something else" means

\(\bf \textit{something}=\cfrac{\textit{some value}}{\textit{something else}}\implies y = \cfrac{\textit{some value}}{x}\)

what's "n"? we dunno
but we know that when x = 6, y =3, thus \(\bf y = \cfrac{n}{x}\implies 3 = \cfrac{n}{6}\implies 3\cdot 6=n\implies \color{blue}{y = \cfrac{3\cdot 6}{x}}\)

what's "y" when x = 9? well \(\bf y = \cfrac{3\cdot 6}{9}\)

Answer 2

\(\bf \textit{something}=\cfrac{\textit{some value}}{\textit{something else}}\implies y = \cfrac{\textit{some value}}{x}\implies y=\cfrac{n}{x}\)

that is

Answer 3

Wdf idk