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What is the common difference in the following arithmetic sequence 7,3,-1,-5

Malia is observing the velocity of a cyclist at different times. after two hours, the velocity of the cyclist is 15 km/h. after five hours, the velocity of the cyclist is 12 km/h. part a: write an equation in two variables in the standard form that can be used to describe the velocity of the cyclist at different times. show your work and define the variables used. (5 points) part b: how can you graph the equations obtained in part a for the first 12 hours? (5 points) if you can try and make this as little confusing as you can

The perimeter of a triangle is 69 cm. the first is 5 cm shorter than the second side. the third side is twice as long the first side. find the length of each side