I need help on this homework

What is the ratio of the change in y-values to the change in x-values for this function? a) 1: 13 b) 2: 5 c) 5: 2 d) 13: 1

The area of a rectangle is 54x^9y^8 square yards. if the length of the rectangle is 6x^3y^4 yards, which expression represents the width of the rectangle in yards

What is the number 321,000,000 in scientific notation? also what is the number? ?