Question

Which is the direct linear variation equation for the relationship?

y varies directly with x and y = 12 when x = 4.

Answer 1

y = x-8

Answer 2

The equation should be in the formy=kx
where k is a constant. We know that y=4 when x=12, so plug these values in the equation and solve for k.

Answer 3

y = x - 8 ????

Answer 4

hmm

Answer 5

yeah his/her second reaply was right
idk why he/she post y = x-8
i guess typo or something :..

Answer 6

hmm I should have said find "n" rather =)
or the constant of variation
\(\bf \begin{array}{cccllll}
\textit{something }&\textit{varies directly to }&\textit{something else}\\ \quad \\
\textit{something }&={\color{red}{ \textit{some value }}}&\textit{something else}\\ \quad \\
y&={\color{red}{ n}}&x&\implies y={\color{red}{ n}}x
\end{array}\\ \quad \\
y = 12 \qquad x = 4\implies 12={\color{red}{ n}}4\qquad \textit{find "n" and plug it back in the equation}
\\ \quad \\
{\color{red}{ n}}\to \textit{constant of variation}\)