in environmental engineering, the following equation can be used to compute the oxygen level in a river downstream from a sewage discharge: k = Y – 20(e-0.2x – e-0.75x) where x is the distance downstr

in environmental engineering, the following equation can be used to compute the oxygen level in a river downstream from a sewage discharge: k = Y – 20(e-0.2x – e-0.75x) where x is the distance downstream in kilometers (km). With the constant 10