Try this X varies directly as y and jointly as z, and x = 20, when y=3 and z= 4 a. Find the constant b. What is the formula connecting X, y and z c. Find x when y=6 and z= 10

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

Which graph represents the following piecewise defined function?

Any is very appreciated! (picture is provided below)not sure how to do this at all won't lie