$A$ system does $200 \, J$ of work and at the same time absorbs $150 \, J$ of heat. The magnitude of the change in internal energy is $..... \, J.$ (Nearest integer)

For the reaction $C_{(s)} + \frac{1}{2}O_{2(g)} \to CO_{(g)}$ at constant $T$ and $P$,which of the following statements is correct?

$A$ gas expands isothermally against a constant external pressure of $1 \ bar$ from $10 \ dm^3$ to $20 \ dm^3$ by absorbing $800 \ J$ of heat from the surroundings. Calculate the value of $\Delta U$. (in $J$)

What is the change in internal energy if a system does $140 \ kJ$ of work on the surroundings and $40 \ kJ$ of heat is added to the system (in $kJ$)?

If $2 \ kJ$ of heat is released from the system and $6 \ kJ$ of work is done on the system,what is the internal energy change $(\Delta U)$ of the system?

What is the value of the increase in internal energy when a system does $8 \ J$ of work on the surroundings by supplying $40 \ J$ of heat to it (in $J$)?