determine whether y varies directly with x. If so, find the constant of variation and write the equation. yes; k=4 and y=4xyes; k = -4 and y= -4xyes; k = -4 and x= -4yno(please help me)

determine whether y varies directly with x If so find the constant of variation and write the equation yes k4 and y4xyes k 4 and y 4xyes k 4 and x 4ynoplease he class=

Respuesta :

Given the information on the table, we can find out the constant of variation by working a few cases:

[tex]\begin{gathered} k=\frac{y}{x} \\ \Rightarrow k_1=\frac{-8}{-2}=4 \\ k_2=\frac{-16}{-4}=4 \\ k_3=\frac{-24}{-6}=4 \end{gathered}[/tex]

Therefore, k=4. To find the equation we simply solve for y the first equation:

[tex]\begin{gathered} k=\frac{y}{x} \\ k=4 \\ \Rightarrow4=\frac{y}{x} \\ \Rightarrow4x=y \end{gathered}[/tex]

Finally, the equation is y=4x