Solve for d:
2d+1/6=6(1/3d+1)

An investment decreases in value by 30% in the first year and decreases by 40% in the second year. what is the percent decrease in percentage in the investment after two years

Which of the following is missing in the explicit formula for the compound interest geometric sequence below?

If 7x=9y, y/z = 7/5 , then x/z = (a) 2/7 (b) 7/9 (c) 9/5 (d) 9/7 (e) 5/9