## Elementary Technical Mathematics

$$m= \frac{2k}{v^2}$$
We multiply both sides by $2$ and then we divide by $v^2$ as follows: $$2k=mv^2 \Longrightarrow \frac{2k}{v^2}= \frac{v^2m}{v^2} \Longrightarrow m= \frac{2k}{v^2} .$$