Estimate the sum of $642.23 and $861.17 to the nearest hundred dollars

Suppose investors can earn a return of 2% per 6 months on a treasury note with 6 months remaining until maturity. the face value of the t-bill is $10,000. what price would you expect a 6-month maturity treasury bill to sell for? (round your answer to 2 decimal places. omit the "$" sign in your response.)

Aheated piece of metal cools according to the function c(x) = (.5)x ? 7, where x is measured in hours. a device is added that aids in cooling according to the function h(x) = ? x ? 2. what will be the temperature of the metal after two hours?

Ineed if you could explain and give me the answer you! this needs done