P₁*V=M₁/Mr*R*T₁
P₂*V=M₂/Mr*R*T₂
P*(2V)=(M₁+M₂)/Mr*R*T
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M₁=P₁*V*Mr/(R*T₁)
M₂=P₂*V*Mr/(R*T₂)
P=(M₁+M₂)/(Mr*2V)*R*T=(P₁*V*Mr/(R*T₁)+P₂*V*Mr/(R*T₂))/(Mr*2V)*R*T=
=T*(P₁/T₁+P₂/T₂)/2= 200*(2e6/800+2,5e6/200)/2 Па = 1500000 Па = 1,5 МПа