Can someone help me with this equation

Graph the line with the given slope m and y-intercept b. m=-3,b=1

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

What are the solutions of the equation x4 + 6x2 + 5 = 0? use u substitution to solve.