X miles per hour - <span> speed of the boat in still water (x - 2) - speed up the river (x + 2) - speed down the river </span> = 30 * (x + 2) = 38 * (x - 2) 30x + 60 = 38x - 76 - 8x = - 136 x = 17 miles per hour - <span>the speed of the boat in still water.</span>