What is the center of the circle with the equation x2 + y2 +4x-8y+11 = 0 ?

Which of the following statements is true? a. the irrational number system is not closed under multiplication, because the product of two irrational numbers is always a rational number. b. the irrational number system is not closed under multiplication, because the product of two irrational numbers is not always an irrational number. c. the irrational number system is closed under multiplication, because the product of two irrational numbers is always an irrational number. d. the irrational number system is closed under multiplication, because the product of two irrational numbers is always a rational numbers. reset submit

Six random samples were taken each year for three years. the table shows the inferred population for each type of fish for each year.

Which of the following statements are true? (select all that apply.) a quasi-static process is one in which the system is never far from being in equilibrium. when a system can go from state 1 to state 2 by several different processes, the amount of heat absorbed by the system will be the same for all processes. the internal energy of a given amount of an ideal gas depends only on its absolute temperature. when a system can go from state 1 to state 2 by several different processes, the work done on the system will be the same for all processes. when a system can go from state 1 to state 2 by several different processes, the change in the internal energy of the system will be the same for all processes. for any substance that expands when heated, its cp is greater than its cv.