What does “z” means in a coordinate plane? plz

The ratio pv to nrt is plotted against pressure for ch4 at 0°c and 200°c. why does the curve for 0°c drop below the horizontal line for an ideal gas whereas the curve for 200°c does not?

Subscriptions to a popular fashion magazine have gone down by a consistent percentage each year and can be modeled by the function y = 42,000(0.96)t. what does the value 42,000 represent in the function?

Identify the polynomial. a2b - cd3 a.monomial b.binomial c.trinomial d.four-term polynomial e.five-term polynomial