Question

determine whether y varies directly with x. if so find the constant of variation and the function rule

y=-2x
y=4x-3

for the second one is the constant of variation 4? what happens to the -3?

Answer 1

\(\bf \begin{array}{cccllll}
\textit{something }&\textit{varies directly to }&\textit{something else}\\ \quad \\
\textit{something }&={\color{red}{ \textit{some value }}}&\textit{something else}\\ \quad \\
y&={\color{red}{ n}}&x&\implies y={\color{red}{ n}}x
\end{array}\\ \quad \\
{\color{red}{ n}}=\textit{constant of variation}\)

Answer 2

First of all, the second equation doesn't vary directly because there is a y intercept, if b in y=mx+b does not equal zero, then there is no direct variation.