Me solve this

10 elves each made 10 xylophones. each xylophone had 10 keys. they did this for 10 days. how many keys were made by the elves? show in exponential form and solve.

Margaret is purchasing a house for $210,000 with a 15 year fixed rate mortgage at 4.75% interest she has made a 5% down payment the house is valued at 205,000 and the local tax rate is 3.5% homeowners insurance 600 per year what are her total monthly payment