Please answer 15 and 16 please

The speed of a falling object increases at a constant rate as time increases since the object was dropped. which graph could represent the relationship betweent time in seconds, and s, speed in meters per second? speed of a falling object object over time

What is the value of x in the following equation? -3x-2=2x+8

Atriangle has a side lengths of 18cm, 80 cm and 81cm. classify it as acute obtuse or right?