The toy robot moves a total distance of 400 centimeters in 20 seconds. What is the time in seconds the toy robot moves when the total distance is 900 centimeters

What is the missing step in this proof ?

The federal reserve controls certain interest rates in the united states. investors often try to speculate as to whether the federal reserve will raise or lower rates and by how much. suppose a company conducts extensive interviews with financial analysts, and as a result, predicts that "thefed" will increase rates by an average of 0.25 percentage points every six months for the forseeable future. which type of equation could be used to model the predicted interest rates over the next several years, assuming no other significant changes? a) a linear equation b) a quadratic equation c) a polynomial equation d) an exponential equation

David leaves his house to go to school. he walks 200 meters west and 300 meters north. how far is david from his original starting point?