A bridge is expected to have maintenance and repair expenses of $20,000 in the first year. It is expected that these expenses will increase $5,000 per year thereafter during the bridge expected life of 50 years. What is the present worth of these expenses for the 50-year life of the bridge using interest at 8%?

ans : $942,550

A contract provides an income of 25 decreasing annual payments starting with $10,000 at the end of the first year and decreasing at the rate of $200 per year each year. Thus his last receipt at the end of the 25th year is $5200. What is the uniform annual equivalent of these 25 payments (i = 6%)?

ans : $8,186

I know these are the correct answers but I am not sure how to do the work to get them please help