Question 524948
Sara travels at a speed of 50 kilometers per hour from t=0 until t=3 Then she continues in the same direction at a speed of 40 kilometers per hour.

Find st Sara's average speed at any time t which is larger than 3.
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Avg speed = (150 + 40t)/(t+3)
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I have to find the equation for s(t)
s(t) = 150 + 40*(t-3) for t>= 3
s(t) = 50t for t < 3