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Your pump empties the water from a swimming pool in 8 hours. When your friend's pump is used together with your pump, the pool is emptied in 2 hours and 40 minutes. How long (in hours) does it take your friend's pump to empty the pool when working alone?

Acable company wants to provide cell phone service for residents on an island. the function for the cost of laying the cable from the island to the mainland is c(x)= 6.500 square root x2+4, where x represents the length of the cable in feet. what are the domain and range of the function? a) domain: all real numbers range: all real numbers greater than or equal to 17,000 b) domain: all real numbers greater than or equal to 0 range: all real numbers greater than or equal to 17,000 c) domain: all real numbers greater than or equal to 0 range: all real numbers greater than or equal to 13,000 d) domain: all real numbers greater than or equal to 13,000 range: all real numbers greater than or equal to 0

Do some research and find a city that has experienced population growth. determine its population on january 1st of a certain year. write an exponential function to represent the city’s population, y, based on the number of years that pass, x after a period of exponential growth. describe the variables and numbers that you used in your equation.

The vertex of this parabola is at (-2,-3). when the x-value is -1, the y-value is -5. what is the coefficient of the squared expression in the parabola's equation?