緩やか: a gentle slope and gradual sales recovery
Read 緩やか as a modifier of a riverside slope or an ongoing recovery, distinguishing terrain from the pace of change.
The gentleness of the slope
川沿いには緩やかな坂道が続いている。 describes a gentle slope running along the river. 緩やか, read ゆるやか, modifies 坂道 and describes the slope's gradient.
川沿い and 続いている supply the riverside location and continuation. The sentence gives neither a walking speed nor the slope's exact angle.
Sales recovering since spring
売り上げは春から緩やかに回復している。 says that sales have been recovering gradually since spring. 緩やかに modifies the ongoing 回復している and describes the gradual change.
春から supplies the starting reference. Ongoing recovery is not a report of complete return to a previous sales level, and no numerical recovery rate is given.
Locate what 緩やか modifies
The slope example concerns a gentle gradient; the sales example concerns gradually progressing change. Their modifier targets distinguish the two uses of 緩やか.
Neither a travel speed on the slope nor a sales recovery percentage is supplied. The learning question concerns what is gradual or gentle rather than calculating an unstated value.
What does 緩やか modify in 緩やかな坂道 and 緩やかに回復している?
Show the answer and why
It describes the slope's gradient in the first and the gradual progress of sales recovery since spring in the second. Walking speed and a completed recovery figure are unstated.