Well, the ideal gas law tells us that pressure times volume equals number of moles times a constant R times temperature t.
From that, when we keep pressure constant and the number of moles constant, we get Charles Law or v one over t one equals V two over t two. And when we graph this, we get the following. Suppose we graph it at one ATM, we get a linear relationship. If we graph it at three ATM, we also get a linear relationship. If we graph it at five at M, we also get a linear relationship. Now, at any other temperature, it would also show a linear relationship.