Find the common ratio of the geometric sequence 9, -18, 36, ...

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

When i add money am i supposed to make it like this 7+12 or 7.00+12.00 because i got 19 dollars for my answer

5,600 x 10^3 = a) 560 b) 5,000,600 c) 5,600,000 d) 56,000