The supply store sells 4 pencils for every 5 pens the store sold 28 pencils yesterday how many pens did it sell

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

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36

Akayaker travels 3 miles upstream and 3 miles downstream in a total of 4 hours. in still water, the kayaker travels at a speed of 2 mph. what is the average speed of the river's current?