Please Help How is an object's acceleration affected by its mass and the forces acting on it?

An astronaut drops a rock into a crater on the moon. the distance, d(t), in meters, the rock travels after t seconds can be modeled by the function d(t)0.82. what is the average speed, in meters per second, of the rock between 5 and 10 seconds after it was dropped?

You paid 28.00 for 8 gallons of gasoline. how much would you pay for 15 gallons of gasoline?

How many solutions does the nonlinear system of equations graphed bellow have?