Mr. Mole left his burrow that lies below the ground and
started digging his way at a constant rate deeper into
the ground. After 5 minutes of descending at a rate of
1.8 meters per minute, he was 13.5 meters below the
ground.
Let y represent Mr. Mole's altitude (in meters) relative to
the ground after 2 minutes.
Complete the equation for the relationship between
the altitude and number of minutes.