Question restated. which is not equivalent to d = rt? r = t/d r = d/t t = d/r d = tr If we divide both sides of the original equation by t, we are left with r = d/t, so we know that this is true. if we compare this, however, with the first item on the list, we can see that t/d does not equal d/t, so the first item on the list is the wrong one.