A boat on the the ocean is [math] km from the nearest point on a straight shoreline; that point is [math] km from a restaurant on the shore. A woman plans to row the boat straight to a point on the shore and then walk along the shore to the restaurant. If she walks at 5 km/h and rows at 4 km/h. How far will the point on shore be from the restaurant if she plans to minimize her total travel time?

Distance from restaurant =