In items 1 & 3, Write each series in sigma notation

1. -8 - 18 - 32 - 50 - 72 2003. Prove that Em = n(n +2)(n - 1).4. 7" - 2" is divisible by 5. 5. One morning, on the way to the market, you exchange your pig for some magic dark round chocolates . These chocolates have the property that every night at midnight, it splits into two, effectively doubling your collection. You decide to take advantage of this and each morning (around 8am) you eat 5 pieces of it. Explain why it is true that if at noon on day n you have a number of chocolates ending in 5, then at noon on day n + 1 you will still have a number of chocolates ending in 5