after a heavy rain, a river reached the edge of its banks. any more rain and there would be a flood after a few hours, the river went down 1/5 inch. theb another rainstorm hit and dropped 1/4 inch of rain. the river rises by 1/20 of amount of rain that falls. usr this rxpression -1/5 + 1/4/20/1 to find how the new water level compares to the riverbank. did the new rain cause a flood?