Please help!!
9. Multiply. x+2/5x-15 times (10x^2-25x-15)
21. Do the data in the table represent a direct variation or an inverse variation? Write an equation to model the data in the table.
x- 1 2 5 10
y-6 12 30 60
23. What are the excluded values of the function? y=-2/5x+40