Given:
[tex]y=x^2+6x-1[/tex]
[tex]\dfrac{x}{r}=-3[/tex]
To find:
The given equation in terms of r if [tex]\dfrac{x}{r}=-3[/tex].
Solution:
Given that,
[tex]\dfrac{x}{r}=-3[/tex]
[tex]x=-3r[/tex]
We have,
[tex]y=x^2+6x-1[/tex]
Substitute x=-3r in the above equation.
[tex]y=(-3r)^2+6(-3r)-1[/tex]
[tex]y=9r^2-18r-1[/tex]
Therefore, the required equation in terms of r is [tex]y=9r^2-18r-1[/tex].