{\displaystyle {\frac {V_{1}}{T_{1}}}={\frac {V_{2}}{T_{2}}}\qquad \mathrm {or} \qquad {\frac {V_{2}}{V_{1}}}={\frac {T_{2}}{T_{1}}}\qquad \mathrm {or} \qquad V_{1}T_{2}=V_{2}T_{1}}