We know that,

Work done = force ×displacement

Volume = area ×displacement

Therefore,

Work done=pressure ×volume

Let change in the volume of system = ΔV = V₂-V₁

Pressure =P

Thus, work done by the system W

ΔW=PΔV

It is given that volume in increasing i.e. ΔV>0. So, ΔW>0 and positive.

From ideal gas equation, we know that

PV=nRT

Where P=pressure

V=volume

n=number of moles

R=gas constant

T=temperature

So, if both pressure and volume are increasing, then

the temperature must also increase as n and R are constant.