can someone help me pls

Answer: [tex]\bold{k=\dfrac{Fr^2}{qQ}}[/tex]
Step-by-step explanation:
Isolate k by multiplying both sides of the equation by [tex]\dfrac{r^2}{qQ}[/tex]
[tex]F=k\dfrac{qQ}{r^2}\\\\\\F\bigg(\dfrac{r^2}{qQ}\bigg)=k\dfrac{qQ}{r^2}\bigg({\dfrac{r^2}{qQ}\bigg)[/tex]
[tex]\large\boxed{\dfrac{Fr^2}{qQ}=k}[/tex]