Kayden is a stunt driver. One time, during a gig where she escaped from a building about to explode(!), she drove at a constant speed to get to the safe zone that was $160$ meters away. After $3$ seconds of driving, she was $85$ meters away from the safe zone. Let $D(t)$ denote the distance to the safe zone $D$ (measured in meters) as a function of time $t$ (measured in seconds). **Write the function's formula.** $D(t)=$ [[☃ expression 1]]