18. Nidhi bought two pens, for * 30 and 3 20 respectively. She sold the first pen at a profit of
10% and the other pen at a loss of 10%. Find
her profit or loss percent

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827

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

Drag statements and reasons to each row to show why the slope of the line between d and e is the same as the slope between e and f, given that triangles a and b are similar.