Question

Assume the y varies inversely with x and y = -3 when x = 4. Write the indirect variation equation for the relationship.

Answer 1

Start with the general form for inverse variation: y = k/x where k is a constant.

Answer 2

Now, all you need to do is figure out what k is. Since they gave you x and y values, you can substitute them into your formula.

Answer 3

\(\bf \begin{array}{cccllll}
\textit{something }&\textit{varies inversely to }&\textit{something else}\\ \quad \\
\textit{something }&=\cfrac{{\color{red}{ \textit{some value }}}}{\textit{something else}}\\ \quad \\
y&=\cfrac{{\color{red}{ n}}}{x}
&&\implies y=\cfrac{{\color{red}{ n}}}{x}
\end{array}
\\ \quad \\
y=-3\qquad x=4\qquad -3=\cfrac{{\color{red}{ n}}}{(4)}\)

solve for "n" to find the "constant of variation", then plug it back in the original equation

Answer 4

That actually helped a lot, I haven't tried it. Thanks!

Answer 5

Yes, what jdoe said is correct