- Qúa trình đẳng nhiệt
\(P_1.V_1=P_2.V_2\\ \Leftrightarrow2.10^5.V_1=5.10^5.\left(V_1-4,5\right)\\ \Leftrightarrow\frac{V_1}{V_1-4,5}=\frac{5.10^5}{2.10^5}=\frac{5}{2}\\ \Leftrightarrow2V_1=5V_1-22,5\\ \Leftrightarrow3V_1=22,5\\ \Leftrightarrow V_1=7,5\left(l\right)\)