R 4 R 3 + R 4 × ( 1 + R 2 R 1 ) × v a − R 2 R 1 × v b {\displaystyle \frac{R_4}{R_3 + R_4} \times (1 + \frac{R_2}{R_1}) \times v_a - \frac{R_2}{R_1} \times v_b}
