Pls help with question 2 and 3

What number should be added to both sides of the equation to complete this square? x^2-10x=7

You have just applied, and have been approved for a $58,000 mortgage. the rate quoted to you by the lender is 6.1% for a 30 year fixed mortgage. determine how much of your third month’s payment goes towards the principal. $56.65 $56.93 $57.22 $57.51

Apasta salad was chilled in the refrigerator at 35° f overnight for 9 hours. the temperature of the pasta dish dropped from 86° f to 38° f. what was the average rate of cooling per hour?