$$\mathbf{E =}\frac{\mathbf{procentowa\ zmiana\ wielkosci\ popytu/podazy\ }}{\mathbf{procentowa\ zminana\ czynnika\ wplywajacego\ na\ popyt/podaz}}$$

$$\mathbf{\text{Ep}} = \frac{procentowa\ zmiana\ wielkosci\ popytu}{procentowa\ zminana\ czynnika\ wplywajacego\ na\ popyt}$$

$$\mathbf{\text{Ep}} = \ \frac{\mathbf{\%\ Q\ }\mathbf{D}_{\mathbf{x}}}{\mathbf{\%\ }\mathbf{P}_{\mathbf{x}}} = \frac{100\%\ \frac{QD_{x}}{QD_{x}}}{100\%\ \frac{P_{x}}{P_{x}}} = \ \frac{QD_{x}}{QD_{x}}*\ \frac{P_{x}}{P_{x}} = \ \frac{\mathbf{Q}\mathbf{D}_{\mathbf{x}}}{\mathbf{P}_{\mathbf{x}}}\mathbf{*\ }\frac{\mathbf{P}_{\mathbf{X}}}{\mathbf{Q}\mathbf{D}_{\mathbf{x}}} = \mathbf{f}^{\mathbf{'}}\left( \mathbf{P}_{\mathbf{x}} \right)\mathbf{*}\frac{\mathbf{P}_{\mathbf{x}}}{\mathbf{f(P}_{\mathbf{x)}}}\ $$

$$\mathbf{E}_{\mathbf{m}} = \ \frac{\mathbf{\%\ Q\ }\mathbf{D}_{\mathbf{x}}}{\mathbf{\%\ }\mathbf{P}_{\mathbf{x}}} = \ \frac{\mathbf{Q}\mathbf{D}_{\mathbf{x}}}{\mathbf{P}_{\mathbf{x}}}\mathbf{*\ }\frac{\mathbf{P}_{\mathbf{y}}}{\mathbf{Q}\mathbf{D}_{\mathbf{x}}} = \mathbf{f}^{\mathbf{'}}\left( \mathbf{P}_{\mathbf{\text{yx}}} \right)\mathbf{*}\frac{\mathbf{P}_{\mathbf{y}}}{\mathbf{f(P}_{\mathbf{y)}}}$$

$$\mathbf{E}_{\mathbf{\text{dp}}} = \ \frac{\mathbf{\%\ Q\ }\mathbf{D}_{\mathbf{x}}}{\mathbf{\%\ \ DP}} = \ \frac{\mathbf{Q}\mathbf{D}_{\mathbf{x}}}{\mathbf{DP}}\mathbf{*\ }\frac{\mathbf{\text{DP}}}{\mathbf{Q}\mathbf{D}_{\mathbf{x}}} = \mathbf{f}^{\mathbf{'}}\left( \mathbf{\text{DP}} \right)\mathbf{*}\frac{\mathbf{\text{DP}}}{\mathbf{f(DP)}}$$

$$\mathbf{E}_{\mathbf{S}} = \ \frac{\mathbf{\%\ Q\ }\mathbf{S}_{\mathbf{x}}}{\mathbf{\%\ \ }\mathbf{P}_{\mathbf{x}}} = \ \frac{\mathbf{Q}\mathbf{S}_{\mathbf{x}}}{\mathbf{}\mathbf{P}_{\mathbf{x}}}\mathbf{*\ }\frac{\mathbf{P}_{\mathbf{X}}}{\mathbf{Q}\mathbf{S}_{\mathbf{x}}} = \mathbf{f}^{\mathbf{'}}\left( \mathbf{P}_{\mathbf{x}} \right)\mathbf{*}\frac{\mathbf{P}_{\mathbf{x}}}{\mathbf{f(P}_{\mathbf{x)}}}$$