What is the average rate, in m/s, at which these 6 dolphins swam during this observation? i know the answer is 64 but i wanna know how to do it.

You would just add up all of the values and divide by six to get the average

Total Distance = (40 x 10) + (60 x 20) + (30 x 20) + (90 x 30) + (50 x 30) + (80 x 40) = 9600 m

Total time = 10 + 20 + 20 + 30 + 30 + 40 = 150 sec

Average = 9600 ÷ 150 = 64m/s

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64m/s

what is a pre-existing condition claus?

means if you're already damaged some way when you take out a medical insurance you will not get full compensation for that injury that you already have.

the answer is (4,3)

since the rule for r0, 90º is (-y,x) and it was already applied to form the image, all you have to do is reverse the answer using this formula.