Which expression is equivalent to the following? (5×10^−3)+(6×10^−3) divided by 2.2×10^4 A. 5 x 10^-7
B. 5 x 10^-1
C. 5 x 10^-10
D. 5 x 10^7

Someone me i need with this stuff

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

The product of 3 and a number increased by 8 is 31 written as an equation