Solution

Assuming we're working with ideal gases
We have:
$V_1=2L=2 \cdot 10^{-3} m^3$
$P_1=0.8MPa$=0.8 \cdot 10^6 Pa$$V_2=10L=10 \cdot 10^{-3} m^3$for an isothermical process, the work done is$W=nRT\ln(\frac{V_2}{V_1})$but$P_1V_1=nRT$, then$W=P_1V_1\ln(\frac{V_2}{V_1})$and calculating we get$W \approx 2575J$