X = 1 + 2^3 + 4*5 - 6*7^8

##</code><code>##

Pressures=-16.6999-(0.0101059*Temperature)+(0.00116512*(Temperature^2))+(0.1733554*(Temperature)*(Volumes))+(4.24267*(Volumes))-(0.0684226*(Volumes^2))

##</code><code>##

$temp = 40;
$vol = 2.5;
$pressure=(-16.6999)-(0.0101059*$temp)+(0.00116512*($temp^2))+(0.173354*$temp*$vol)+(4.24267*$vol)-(0.0684226*($vol^2));