At 9am the temp was -10 degrees f and at noon it was 28 degrees f. how much did the temp change? ((i already tried doing -10+28=18 but my teacher said it was wrong))

What is the binomial expansion of (2x-3)^5

Mexico city, mexico, is the world's second largest metropolis and is also one of its fastest-growing cities with a projected growth rate of 3.2% per year. its population in 1991 was 20,899,000 people. use the formula p = 20.899e0.032t to predict its population p in millions with t equal to the number of years after 1991. what is the predicted population to the nearest thousand of mexico city for the year 2010?

Me because i don't understand how to do it.: )